Anode gone after 4 years / Water heater failure. Soft water

I have a customer whose water fails often. Heater lasted 4.5 years. I pulled anode which was down to only the wire. House has soft water service that changes out the tank on a regular basis. There is a recirculating system tied to the water heater with a Grundfos pump. Receptacle that serves the pump appears to be wired correctly. I'm in So. Cal so the water here is hard. There is an expansion tank on the heater. Do you think bonding the hot, cold, recirc & gas line together?

 

There is likely a little bit of salt ions in the water which makes things more conductive. I think you'll just need to change the anode rod more frequently. Bonding the WH won't hurt, may not help.

 

That is what I alwsys do when that happens, and seems to stop the problem.