The size difference between 205 and 215 is small enough that they probably will not rub on the body; although if your car has been lowered, or if it has tight clearance around the wheels; it would be worthwhile to check with a dealership or with www.tirerack.com to make sure they will fit.
The effect of larger tires would be to slightly reduce the engine speed on highway driving (like shifting to a slightly higher gear). The difference between these two sizes would be very small; and might not even be noticeable under most conditions. The increased height of the wheels would have a small effect on the wheel alignment. In some cases; it might lead to less even tire wear from the inside to outside edge. But here again; with such a small change, I would not expect this to be a problem.
Many owners go to the next size larger tires on their cars; and usually get longer tire life and better handling as a result.