Several things here.

The BRIDGE is ancient technology, and had been originally replaced by the BOOST, and now, that also appears to have been retired, leaving either WiFi connection, or direct wiring. The BRIDGE in particular is known to sometimes have a power supply issue that can cause difficult to trace connection issues, so it should be retired ASAP. I would set up your PLAY:5 gen 1 to use WiFi, or direct connection, using the instructions in the wireless and wired systems FAQ. 

If you still use the S1 app to connect to your first generation PLAY:5, that’s fine, but during setup of S2 devices, I’d recommend unplugging the PLAY:5 gen 1 (and any other S1 products in your system) from power, so there is no ‘confusion’ of the two systems. Once everything is set up, you can power them back up again. 

If you have surround speakers connected to your PLAYBAR, remove them before connecting your Sub, you can add them back once it is connected.

There’s a lot here, you might be better off, since you’re not a ‘teck’ (sic) person, to call Sonos Support directly to discuss things, and help you get to where you want to be.

 So the Playbar & Sub gen1 were “Bonded” in the S1 app, but will not “Bond” in the S2 app?  Is the Sub seen in the S2 app?  Do you intend to use the Sub with the Arc?

Hi you two and thanks for replying.  
I think I may have solved some of the issues by re booting my router. The sub has now been recognised and is very slowly being installed I hope. 
Yes my intention is to use the new Arc with the Sub. I’ve paid for installation along with my new TV so hopefully they’ll sus it out. 
Otherwise I feel a call to support as suggested will be on the cards. Lol. 
I think I’ve got my Play 5 on the Sonos 1 app now but haven’t tested it.  
Still I’m learning lots.