If you want to use talkgroups, then you have to set the TX contact on your transceiver to the talkgroup ID.
Also to hear the openSPOT2's voice announcements, it is recommended to create an RX group list in your transceiver, put TG9 into this list and assign this RX group list to all channels you use for the OS2.
If you'll get comfortable using talkgroups, then you can try the call rerouting feature of the openSPOT2. Call rerouting is described in the user manual on this page:
http://manuals.sharkrf.com/openspot2/en/homebrew-mmdvm-connector.html