I don't really roleplay and when I do go to a club and they have a bartender I just ask for a random drink and it works, venue people are generally nice and will go along with you. Think you overthink things, just try something and if it works cool and if the venue or people have an issue they will send you a tell. Like the tells you get to hide a minion, or the tells I get to come back down when I go into a VIP only area >.>