Although I see it on the OBi website, Vonage Home accounts cannot be connected to my OBi202. Vonage confirmed that it won't configure unless you use a Vonage Business account.
What and where are you seeing it on the Obihai web site?
I don't think Vonage has ever given residential customers their SIP credentials. The OBiTALK template for Vonage is only for business accounts, as you were told.