Do the WET200 have to be operated as a pair, i.e. be on both networks when used as a bridge, or can they interoperate with any brand on one side of the bridge?

I am trying to create a wireless bridge between a network with ip's 198.1.1.xxx (this network has the gateway) to a network with ip's 198.1.2.xxx -  so that it can access the internet thru the gateway).  Both AP's are WAP54G set to bridge mode. Both ...