So it appears I have finally got it working, although its not how I figured it would of worked....
ERX1 on switch0
eth1-PVID 100
eth2-PVID 200
eth4-VID 100
eth4-VID 200
ERX2 on switch0
eth4 VID 100
eth4 VID 200
eth3 PVID 100
eth2 PVID 200
eth1 PVID 200
I can't tunnel in via wireless now, but I guess its still improvement.
I hope this helps others.