I believe the OBi100 stays connected to GV. If you go to the Status screen, it shows GV connected.
If you route outbound calls to the OBi200 via OBiTalk network you are adding 2 legs to the call. 1 leg to the OBiTalk servers and another to the OBi200 and then out GV. I think you should only do this if you need both SP trunks on the OBi100 for something else.
This is how to do it:
OBi100
Add to the beginning of the Phone Port OutboundCallRoute:
{(<200200200*>1xxxxxxxxxx):pp},
or
{(<200200200*>(Msp1)):pp},
200200200 is the OBi number of the OBi200.
The 1st will route 11 digit numbers.
The 2nd will route any number that matches the ITSP A DigitMap.
OBi200
Voice Services -> OBiTalk Service -> InboundCallRoute:
{100100100>(Msp1):sp1},{ph}
100100100 is the OBi number of the OBi100.