I doubt such system is in works now but certainly was in the past , at least in some bars. Quota of drinks soled or off fees paid. This could make sense when boys were storming bars to get a job there , not now when some bars have visibly trouble attracting new talent.
It's nice for business to keep their employees happy but at end of day they need to pay them and rent somehow and we are not talking about part of economy which can count on direct government handouts