Of course it is but it's not only about how much ale can the character consume its about the fact that this character is the number one expert on all things taveran and pub related and all it's entail, need to find some shady character in the slums? the pub crawler will have an inkling where to start looking, need to bluf your way through a throng of elderly nobles in a fancy party? The pub crawler could try and engage them with talks about wine and brandy while the rest of the party excuse them selves.
That's what I mean with soft mechanics, of course it might translate to plain old +2 to checks but with DM discretion it might not.
Warder
Funnily enough, thats pretty much what I want to see. A nice fluffy definition of the theme. Then if a player can justify that a given action they are taking ties in with the theme, give them a +2 (on top of other modifiers) for managing to tie it to the theme. No skills, no feats, just a theme that provides fluff which can manifest into simplistic mechanics.