dimitri would absolutely go to bars, it'd be the one really normal thing left from his human life, even if the bar wasn't very normal at all :) he's not prejudiced towards other supernaturals, he just expects that everybody's always about to start shit, and is rarely proven wrong. if bran actually doesn't give a shit, they probably get along, cause anyone who's not causing problems is almost certainly going to make it to "friendly" status with dimitri. all he does is clean up after idiots who couldn't keep their heads on straight (or on at all), and if he's that old, i imagine bran's got it together.