You should ask the casino. Depending on the severity of the bug and what you can do with it, your reward might be quite high. Also, remember: they know that if they do not pay you then you are not obliged to tell them anything. Furthermore, they know that if they do not reward bug hunters, those same people could simply sell the information to hackers and other shady characters. So it is in their best interest to reward you. Don't be afraid to haggle over the price and do not let them take you for a chump. Bugs can be very valuable. Although some bugs can be completely worthless.