Rick,
It pays to ask
startpage.com :
From the admin guide:
"LAN Switching Features
Instead of acting as a router, the OBi202 can be set to work as a 3-port switch. One of the ports is internal and is used by the OBi202 CPU only, while the two external ports (labelled as Interent and LAN) can be connected to other devices. This mode of operation is known as the bridge mode. In this mode, all the router features, such DHCP server, firewall and port forwarding, will not take effect.
The QoS policy in this case is hardwired such that the native voice and related traffic will always have highest priority (this behavior is not configurable). Furthermore, accessing the OBi device management web pages from either of the two external ports is always allowed." (emphasis added by me)
So, if you want to configure the QoS, why not place your 2-wire in bridge mode and let the Obi be in charge?
If you can't put the 2-wire in bridge mode (sorry, I'm not familiar with 2-wire) then you could still "double nat" and leave your Obi in router mode. Not ideal, but it usually works alright.
Good luck getting things sorted to your satisfaction.