Best answer by Stanley_4
Check that your Bridge is working properly, some of them have bad power supplies that give frustrating results. The easy thing to do is unplug power to the Bridge and hook an Ethernet cable to another sonos speaker, wait a couple minutes and things should start working. If it is the power supply and you want to keep using the bridge you can get a replacement supply locally or on Amazon.
To keep the sonos gear off your wifi, use the controller to remove the WiFi SSID and pass phrase from your sonos.