wasn't that discreet then, lol.
Your tip was very generous and placed in right hands. I'd try to be even more discreet so mamasans or other boys see nothing. Way I achieve that in similar situation is by placing tip in the back of boys undier or jeans.
Discretion is necessary , I learned it from boys over years, other boys may be jealous and / or ask for a loan seeing he got money and mamasan may ask for her cut whether deserved or not. I can name at least 3 boys who changed venues because of that. Sometimes it's cut throat world out there in bars