That depends on what State you are in, when we owned a business in California you paid ALL employee's no less than minimum wage. But we now have a restaurant in Missouri and here the law states that tipped employee's are to be paid no less than 50% of the required minimum wage (Right to work State), providing they make at least half of the State wage in tips. Our waitresses get paid $3.63 per hour....as long as they make at least $3.63 per hour in tips (which they always do). Tips are earned and not a given, if you get good service the tips will always be there....Bad service, then no tip is expected! same rule should apply anywhere in the world...That's why it's called gratuity! we do not require our wait staff to split any tips with bus boys or dishwashers, but if they choose not to, then don't expect any help when you need it! Our bus boys and dishwashers are all paid the State minimum wage. A tip of 10 or 20 baht is fair as long as your tab is 200 baht or less...If not, you are a "Cheap Charlie"! and I would hope the staff remembers you on your next visit! would you bust your ass for 10 baht? I wouldn't! unless of course your bill is only 100 baht! by the way, standard gratuity is at least 15 to 20% unless you get shitty service.
One more thing.....Managers NEVER get a tip split.......That would create a conflict of interest!