Wireless control has advantages in the case of synchronous cooperative motion control. We consider a wireless feedback control system with multiple plants. In such situation, not only the control performance of individual plants but also the synchronization among the plants is important. However, synchronization errors occur because of packet losses in the wireless channel. In this paper, we propose a relay transmission scheme with predictive control information to reduce the influence of packet losses in the synchronization performance. Numerical examples clarify the reduction of synchronization errors by the proposed scheme.