@oremountain Usually it is the better choice to setup bgp with loopback adapters - I was just to lazy to configure an additional interface and static routes for each IPsec peer.
Maybe you try to reconfigure one peer bgp session directly on a VTI Interface, see if it helps.
In case anyone stumbles across this. The solution is to create a rule on the LAN interface that uses the "default" gateway for packets headed toward subnets that live on the other side of the VTI tunnels. This new rule needs to be higher in the list than the rule that you create which redirects incoming packets to a gateway group.