Depends on how you hook up to the wifi repeater. If you can connect to the repeater with a ethernet cable the dual wan router does not care about what is in the path.
Be aware most people concept of load balancing multiple internet connections is invalid. First there is no way to combine the connections to make say a single file transfer session faster. You might run 2 different ones but even that is tricky. The problem is you have 2 different IP addresses. This causes all kinds of problems. The example most people on this forum understand is say a online game. If you log into the authentication server using the IP on connection 1 and then attempt to play on a world server with connection 2 the IP will be different and...