I have worked in many different bars and it really depends.Some where very really clean others where absolutely

.
Especially the dance clubs.This place i used to work at you had to bleed the juice and soda fountain for about two pitchers each juice cause there was so many mildey and *mushrooms*(yeah thats how they called it...) in it that if you wouldnt it would taste like old socks.
Some places are infested with fruit flies.
And the funny thing is it has nothing to do with how nice and expensive the place is.
Anyway if you go to a college type club i would recomend drinking bottled beer or beverages.