Our sink is not centered under the window, either. Our faucet is configured in a way that is tricky because the faucet's base is "centered" relative to the spout (which is to the left) and the handle (which is attached to the right). It's hard to explain..If you look at the pictures below, you can see what I mean. We had it mounted so that the stream from the spout flows into the drain hole of the sink. Our sink's drain hole is in the center. This faucet placement ended up to the right of center relative to the length (back edge) of the sink. We had the soap dispenser mounted to the left of the faucet to help counter balance the faucet's placement. We are right handed and the soap on the left is no problem at all. As far as the total overall look, I am happy with how things worked out. The fact that the sink & faucet are not in the center of the window does not bother me at all. Have you made any sort of mock up faucet, handle, water filter & air switch? I used a small water bottle with a piece of cardboard taped to it (cut to the approx. size, shape & height of my faucet) to simulate the faucet. You can also make a rough mock up of a water filter with anything around the house. You can put them in various placement scenarios and stand back and see how you like it. If you have the faucet & filter at your home already, then someone can hold them in place for a few minutes while you see if you like it. But, I like the mock up items to be around for a little while (more than a minute) so I can get a better feel for their placement.

Because it's so asymmetrical and close to the door, I would just make the whole wall curtains. Something like this:

Thank you for your comments. I thought I'd share a change of layout plans that I'm pondering considering I didn't like either option with sink in the bay window/dishwasher layout. Spoke to the contractor and we think it's easier to leave the sink where it is, widen the window above it to be the pass thru awning window, widen the current U shape, leave the bay window as is and the 'eat in' kitchen table area. So I'll be down a dining room but that's ok, it's only a few times per year MAYBE that I entertain and need more space. I can put up a temporary dining table elsewhere (or switch over the den to dining room in the future) or make that circular table an extendable to an oval one. I may add a built in bench to the bay window now or down the road. In this layout, it's a little awkward as to what to put in the niche where the pantry is in my drawing below. It's not full height in there and it's currently where I have a sideboard but with my dining room no longer being there after the reno, it should be something else. Pantry cupboards, maybe a little desk with open shelves above? maybe a beverage/coffee station with mini fridge. I know it's a little awkward having the pantry outside the kitchen. That's the only thing that bugs me about this layout. Other option is to put the pantry to the right of the fridge. In my current kitchen this is where there is a desk and open upper shelves that definitely needs to go. It's where all the 'junk' goes like recipe books, telephone, pet food, meds, etc. so I'm drawn to putting lowers and uppers there to hide all the stuff. But it also makes sense to make this the pantry area so it's more accessible than having to walk around the penisula when prepping. So that's the dilemma/question...where to put the pantry. And what to use that niche for. Note, that niche does have a direct sightline to front door so people will see it when they walk in the front door. The area by fridge is hidden from view facing back of house Thanks in advance.

It's a big deal if it will bug you, it's a pretty big deal to fix - risking a lot of broken tile.... A contractor "decided" ...... So. Where was the drawing of the vanity, showing all dimensions. Also question if these are ABOVE your sinks? The error was dumb. You simply line up with center sinks/ and their faucet plumbing. Was the plumbing in place before electrical? Probably. A contractor, an electrician....both are just technicians. You spec, since that puts all the design details on you, failing you have a designer who does that. You're the "decider". Take a pic of the current situation - upload it in a comment box PS..... Why tile before the concrete vanity..EVEN if it floats.....