We all know that El Aurians make great Bartenders. Just as Jeane Luc Picard! But I bet you'd choose other races as bartenders for your Federation ships. Don't know if KDF vessels have bars as they ARE military vessels... complete with mess halls.
Personally, I'd have a Vulcan bartender. They don't drink, and if a lounge/bar brawl were to take place, just having him step out from behind the bar would make everyone calm down and sit back down on their seats.
And they wouldn't be sampling the rare stuff either (which would be saved for celebrations).