Fail over for 2x local wireless bridges?

Hi,
I have two wireless bridges between towers and a RB at each site. (One link is a ubnt AF5 (Primary) and the other is a ubnt PBE-400(standby)

The two sites are simply bridged. ATM im leaving one port disabled on the standby link and manually enabling it when the primary link goes down.
I want to automate this process. I tried using bonding (active backup) but it seems that it only switches over if the port status is down and does not work if the RF link goes down (remote ip is unreachable).

Is there a way to do this with netwatch?
Thanks,

Sure is this possible with netwatch,
Just enable the needed interface if the other link is down, but in an bridged network the far away airfiber ip from the link that is down becomes available when backup is running and netwatch will switch again.