Assuming you have two different Google Voice inbound numbers, and you want to detour those inbound calls through Callcentric, then I suggest getting two different CC free NY State DIDs. I believe you can have two freebies per CC account. The primary CC account number (e.g. 1777277xxxx) can be assigned multiple extensions. Each extension is designated by a 3-digit suffix after the CC number, (e.g. 1777277xxxx101). Each extension becomes a separate, unique SIP registration, so you need to fill in the SIP password field on the CC dashboard for each one (it can be the same password for all extensions if you wish).
You control the routing of those numbers on the CC dashboard, including which number to send as caller ID, and then you simply configure your OBi to use that extension on a given SPx.