Yes you can. I'm currently using Localphone on a vg. I configure my OBi110 via its local web server but you can also use the Expert Configuration pages at
obihai.com.
Whichever, click on 'Voice Service(s)' then click on 'Gateways and Trunk Grps'. Decide which vg you are going to use and tick the 'Enable' box.
The 'Name' field is just for your use so it doesn't matter what you put there.
For access number enter SP1(localphone.com).
The default digit map will work but will incur a 10 second post dialling delay. You can speed that up with the appropriate custom entry.
AuthUserID and AuthPassword as per your personal Localphone values.
Submit that page.
Then go to your 'Physical Interfaces', 'Phone' page and in the OutboundCallRoute field add an entry which selects the vg you chose. Simplest is something like {(<**8:>Xx.):vg5}. In this case dialling **8 before a number will route the call out on vg5. Submit (and if not using Expert reboot the Obi).