It really depends on a lot of factors. First you have to define bottled water and tap water. There are a lot of different sources of the generic term bottled water. Some bottled waters are actually just tap water that a city has bottled, while others are spring water, or water that has been purified in some manner. Others may have been created from a combination of sources, such as tap water that's been purified. The tap water depends on if you're in a city or on a well, how hard or soft the water is in the area, how old the pipes are and what material they're composed of, and if the city adds chlorine or other chemicals to the water. If you want to do the project correctly you'll have to address these factors. It may be better to narrow the scope to something simpler like is spring water from X spring better than tap water from Y city.

it makes sense to think about this now and not later. it makes sense to protect your coffee machine. Your filtered water can feed a supply that then itself branches to the fridge AND to the bar tap / coffee tap. Where the water supply branches to go to the fridge is where you can put a filter behind the scenes, or anywhere else near the fridge, near the sink, or in an unused space around there, even on the far side of the fridge. The additional elbows do not reduce flow by anything significant. It's the filter that will reduce the flow, but this is not a concern for the two lines you are discussing. some people have a filter on all the cold tap in all the faucets, including those faucets that mix with hot water. In that case, they want a higher flow (not a reduced flow) so it's either a cheap filter that doesn't remove much, or it's a 2-tank system. That is what i have seen or heard. anything i write out is given as background information, not a recommendation to take any action. You could have two filters in line: one cheap, one expensive. The cheap one intercepts the bulk stuff; the expensive one does the higher quality job it is supposed to. Cheap might mean a GE bought at HD for 2 or 3 of your cute $20 bills. Expensive might mean the kind of filter that costs many times more than that, and which you can only get from a high end kitchen showroom, and only if you ask. You could put an RO rnear the bar / coffee spot, instead of running RO water through supply lines. (less chance of leaching minerals out of the pipes on the way to the spout). If anyone local tells you that RO is not needed with your water, they may have a very strong point. RO may be overkill, but a high end filter may be good. This is another subject. I don't know what Toronto water is like, speaking minerally; I have heard that it's taken from somewhere deep in Lake Ontario and therefore always really cold even in summer. I suppose that Some of the people who work in high end coffee machine sales or kitchen fixture sales will be able to guide you about minerals.

We have a "whole house" filter on the cold water line that runs to the kitchen (from our utility room, which is where the filter is located). It filters the cold water at the faucet, the water line to the fridge, and the pot filler faucet. It also filters the water going to the newly installed faucet outside, right over the deck under the kitchen window, but this was not by design--that faucet taps into the cold water line under the kitchen sink. Theoretically we could use that filter for all the cold water (that's what it's meant for), but we don't. The filter is by CUNO--AquaPure (the filter housing we have utilizes the APS117 and AP117 filter cartridges--the "S" cartridge removes lime scale and we put that one in when we replaced the original cartridge last month). If you go to the CUNO and AP distributor websites, you can find various filter options. I know when I called CUNO to ask about the two diff cartridges the woman in cust/tech support seemed surprised that we had a whole house filter, but that's what our plumber installs. I'll bet they can help you find the right filter for your needs. FWIW, we don't have a separate tap/faucet for drinking water. We tend to get our drinking water from the fridge dispenser which is double filtered anyway (once by the house filter and then again by the one in the fridge grille).

I can't drink fridge water. It always tastes terrible to me. I have a filtered water cartridge that gives me great-tasting room temperature water. I use that to reuse plastic bottles and I fill rinsed out cognac bottles with filtered water and put those in the fridge. I also use the filtered water for all my cooking, for coffee, soup and everything else. We are on well water now which has a filter coming into the house. So this one is secondary. When we were in the city on city water I put in a filter with ultraviolet to treat the water. Wouldn't use it straight from the tap. I use a drinking water system from WaterontheWeb.com