300-3 (b) "contained in the same raceway" etc. is mainly intended to prevent the hot and neutral, or hot and ground, from forming a loop that has a large area or contains a lot of iron. Those conditions increase the circuit inductance and could limit a fault current to a value that makes the breaker slow to trip, starting a fire somewhere before the trip. If the hot to the subpanel and the hot coming back for the circuit in question were in different conduits, and the neutrals did not run along with them in the same conduits as the hots, then there is a problem. If the hot to the subpanel and the hot coming back are in the same conduit, without the neutrals, then there is no technical problem, but the AHJ may not like it because it complicates the situation and could lead someone later to unknowingly create a problem. Code is whatever the AHJ says.

"I powered down the sub panel and put all the grounds on the left and the neutrals on the right. They are still bonded together as I only have three feeds form the main. " you are very likely to need to add a separate grounding bar to the panel, and possibly two (one on each side). the green bonding screw that ties the neutral bar to the box itslef must be removed. Some panels allow you to remove the bonding between the tqro strips so that one can be used for grounds, the other for neutral but this tends to make a real mess in the panel since every grounded circuit now needs to go separately to each bar. It is often worth the effort to add two grounding bars parallel to the existing neutral bars. This allows the neutral and ground for each circuit to be tied to the respective bars adjacent to the breaker feeding the hot for that circuit. It sounds like you need four #6 connections (though it might be possible to use a smaller ground line). The hots come from a breaker in the main, and the neutral and ground both come from the same point in the main but need to land on their separate bars in the sub. The reason ground and neutral are separated in sub panels is to prevent any current sharing between the ground connection back to the main and the neutral connection. Any voltage drop in the ground connection picks up the grounds in the sub-panel and the ground of every branch circuit is is supplying. Grounds are never supposed to carry current, except during a fault. You want the whole set of grounds to be as close to zero volts as possible.

ronnatalie....I've re-read your e-mail and realize we may be talking about two different things. 1. All the wiring in the house that has been replaced over the years has a hot/neutral and a ground. The neutral bar and the ground bar are connected at the base of the panel. Kind of forms a big "U" around the hot post which the 30+ breakers are hooked onto. Think the electrician took some measure of pride in his work as almost all of the neutrals are on one bus bar and all of the grounds are on the others. But, again, they are connected at the bottom (is that bonding?). 2. The large copper wire in the lug pictured in previous posting does go to the water metal pipe, but as the neutrals and grounds are bonded together, there is a neutral lugged from the service to the top of the other bus bar. 3. My initial post was expressing surprise that the metal breaker box itself was not grounded. The tester touching a hot post to the metal box. Shouldn't that complete a circuit? Just making sure this thing is safe before I move on and ask other questions. Thanks for your input.

The CEB panel is now owned by Eaton (Canada) and known as the type PRL1 panel and it takes type QBH breakers. I believe with that panel you buy an isolated ground assembly and move the neutrals (both the incoming feed and all the branch circuit neutrals) to that. You leave the grounds on the existing bar. These things do NOT have the greatest reputation. You might give serious consideration to replacing it with something more modern while you're mucking around with it.