I've yet to see a "bar" pulled off right on a boat. This one is pretty close. We have a bar in our house (a wrap-around "L" shaped bar that you can walk behind) and when we use it, there are ALWAYS two people standing behind the bar (on the bar tender side), and 4 or 5 on the "customer" side (that's how the space works out), so everyone can face each other and talk. The MAIN point is that everyone has to be able to FACE the group. On a boat, this is REALLY tough to pull off due to space constraints. Usually the bar layout has the people sitting at the bar, sitting alone.
I assume you can raise the seats up to "bar-height", which I think is 28 inches? If they do, that would be awesome. Then the two people in the bar chairs would have enough height to be part of the group in front of them. Otherwise, the bar is really just a wall that separates them. That would be one way to pull this off on a boat (make it so the two in the bar seats go really high, like a bar stool) since you pretty much have to have a regular couch seat in front of the bar (again, boat-space constraints).
If that's the case (and the seats go up to standard bar stool height of 28 inches), there's another problem. I don't see where your feet would go. You either have to have stools with bars connected to the seat post about 6-8 inches from the deck for your feet, OR you need a foot rail on the bar itself (again, 6-8 inches from the deck).
One thing I really like is that you made the bar table pretty narrow. It doesn't need to be "deep". I think how you have it is PERFECT. One problem I see is people tend to lean on our bar at our house. We have scalloped oak "arm-rails" on our bar. Makes it comfy to sit and lean into the bar. The granite looks a little sharp to lean on. Needs a pad, or a rail or something. Something to think about.
The counter tops look great! Great design. If you had an option for darker granite to match the teak table, that's what I would buy. One other thing - That taller counter top section right behind the helm BEGS for a sink. I'm talking a regular bar sink. Stainless steel with a stainless steel faucet. I see the sink (barely) that you incorporated at the end of the bar, but the section behind the helm would work better. You could make the sink bigger over there that way. Then put a refrigerator under it!
One other thing that I've NEVER seen on a pontoon is instead of a bow seat, a port door seat. A lot of boats seem to separate the front of the boat from the back of the boat, and a side-door seat option might work to merge them. Again, I've never seen this done, so if you guys think it's worth while to think about, you guys can run with it. See what you think.
I really like what you've done so far!