Most, if not all, states treat “bonuses” like “wages” when an employee has done everything in his or her power to earn the bonus. Some state appellate courts have explicitly rejected the notion that an employee has to be remain employed to receive a bonus for which he or she has already done all of the work. These states treat such bonuses like wages due and owed to the employee.
As stated earlier, it would appear particularly unwise for the employer to stop payment on the check in this instance. Even assuming the Georgia courts would sanction the above-described “remaining employed” eligibility requirement, OP, you were, in fact, employed when the company issued the bonus check. In theory, you could have traveled to the issuing bank and cashed the check. The fact your bank has placed a 10 day hold on this deposited check would not appear to grant your employer the legal right to stop payment or otherwise withhold the bonus.