Short answer, no.
Longer answer: Google Voice is designed to be your single point of contact phone number, and, as such, people would call that number, which would then forward to other numbers. It is not designed to work backwards from that model, forwarding inbound calls TO the Google Voice number. Unpredictable results are guaranteed.
Aside from that, If I was your telecom administrator, and I found out you were forwarding your VPN-protected, internal phone network's calls to some other service, I'd report you to your manager as violating security.
What many companies do for their mobile/remote workers, is to use a softphone client that runs on a desktop/laptop computer or mobile device, and that client connects via VPN or other secure means, to the same internal network as your Polycom phone. This is especially prevalent with Cisco and Microsoft Skype For Business customers, as well as customers using a managed, cloud-based solution from companies like Ringcentral, Dialpad, etc.
