I think this is likely smoke & mirrors, for several reasons.
1) You are only required to declare current, not future or potential assets.
2) With the lesser bond, Zimmerman made no effort to flee, evade, or otherwise prejudice his bond. Thus a larger bond cannot be expected to make his behavior any better, just inhibit his ability to defend himself in court.
3) Nothing outside the publicity to the trial entices Zimmerman to leave, other than fear of attack from people agitated by the case. Thus arguments for “holding him for his own protection” are invalid, unless he solicits them.
Don't the New Mulatto Panther Party still have a bounty out on him?