Interesting Post and a problem even here in Las Vegas. Bouncers have sort of been given Carte Blanche to whail on folks at the slightest provocation with NO reprocussions. One case happened here recently at a strip bar..
Problem is there is usually no follow up by Law Enforcement as the parties involved had been drinking. There is usually power in numbers and it is always recommended that when finding entertainment in those establishments to not go in alone, and even when you are there in numbers, keep the lip zipped.
In South Africa it has to be worse as there is virtually no Law Enforcement left to do any follow up......on the other hand if its really serious, there are ways to even the playing field...........