Agree that chest hair shouldn't show in normal situations (in a bar, it's up to the intended prey - but I'm not sure it'll work there either, unless we're talking about those bars where one wears not polo shirts but leather harnesses).
I don't like undershirts that show, however. So the solution is to button up enough. (And shave one's chest, though in any case showing significant amounts of chest, even if shaved, doesn't seem gentlemanly).
Edit: I meant to say wax, not shave.