Hello it's been awhile,
I've done additional testing, and I've found that a group policy applied to a specific network doesn't apply to traffic entering the site to site vpn tunnel. In the a group policy named "public" at site A, I've denied "any" access to server-192.168.1.1 that sits across the site to site vpn at site B. I applied this policy to vlan 120 10.0.10.0/24.
In the site to site vpn firewall, I allow "any" access from 10.0.10.0/24 to 192.168.1.1.
I've found that devices in the 10.0.10.0/24 network can still communicate with the server-192.168.1.1.
Unless I'm doing something wrong, it appears that the site to site vpn firewall rules take precedence over a group policy applied to a vlan subnet.