In the Philippines prostitution is illegal, but it is legal for a bar customer to pay the bar for the priviledge of taking a "GRO" (Guest Relations Officer) away from her job of "entertaining" men who come into the bar. The "Bar Fine" is money paid to the bar to take one of these girls away from the bar, usualy for sex, eventhough that may not be discussed. Typically the bar keeps half of the bar fine and the GRO will get the other half. The "Maddam" (usuly an older prostitute) who is in charge of the GROs collects the bar fine. Within reasonable time limits, if the bar fined GRO is a nonperformer the usual arrangement is to return the GRO to the maddam who will either return the bar fine to the customer or find a more accomodating date for the customer. Beware, tipping the GRO directly is often expected also.
Even though John thought the bar fine was excessive, he paid the maddam the 4500 pesos and took the GRO he liked back to his room for all night sex.