CCP §996.250: (a) An additional or supplemental bond does not discharge or affect the original bond.

(a) An additional or supplemental bond does not discharge or affect the original bond. The original bond remains in full force and effect as if the additional or supplemental bond had not been given. (b) After an additional or supplemental bond is given, the principal and sureties are liable upon either or both bonds for injury caused by breach of any condition of the bonds. Subject to subdivision (c), the beneficiary may enforce the liability on either bond, or may enforce the liability separately on both bonds and recover separate judgments of liability on both. (c) If the beneficiary recovers separate judgments of liability on both bonds for the same cause of action, the beneficiary may enforce both judgments. The beneficiary may collect, by execution or otherwise, the costs of both proceedings to enforce the liability and the amount actually awarded to the beneficiary on the same cause of action in only one of the proceedings, and no double recovery shall be allowed. (d) If the sureties on either bond have been compelled to pay any sum of money on account of the principal, they are entitled to recover from the sureties on the remaining bond a distributive part of the sum paid, in the proportion the amounts of the bonds bear one to the other and to the sums paid.