Originally Posted by jordyn

Nit: this isn't correct. Virgin Trains and Virgin Rail Group (its parent) are majority-owned by Virgin Group, which is also the majority owner of Virgin Atlantic. In other words, both are subsidiaries controlled by the same parent in much the same way that American Airlines and Envoy are both subsidiaries of American Airlines Group.

Having said that, I have no idea if either Delta or Virgin has the ability to book train segments on Virgin Trains, but I agree this is an unlikely solution.