There are two things that this may be....
it may be, as you are thinking, that the frame is slightly bent. Then again, it may be that the rear wheel is not dished correctly. Here's how two find out which it is. Take your rear wheel out and put it back in backwards. In other words just reverse it so that the cassette in on the oposite side. Now look at the spacing of the tire between the stays. If the tire is now off center to the oposite side, your wheel in dished incorrectly. If it is the same then the frame is slightly bent. Once you find this out you know what to tell the guys at the LBS. If the dish is off it's an easy fix, just tell them that the dish is off on the rear wheel and they'll know what to do. If it's the frame, that's another story. It will depend on how badly the frame is tweaked as to whether or not they'll be able to make any adjustments or not. For the most part aluminum frames don't take too well to being bent very much. So much so that most shops don't even have the tools to realign a frame with anymore, too expensive and usually not worth the trouble. Unless of course they deal with allot of steel frames, steel is easy to realign. Anyway it would more than likely be a warranty issue with Jamis, unless of course it's a used frame and you're the second owner.
So reverse the rear wheel and see if the off set does a flip-flop. If so it's the wheel, if not it's the frame. Either way you'll need to go take it in to the shop.