I went ahead and added Slot Machines and the Wheel into my server in Outpost as it doesn't have Bandit Camp on my custom map. I added big wheel terminals around the chairs near the big wheel but none of them show the correct time for the big wheel nor can you actually play, just deposit scrap. Is there any way to "sync" the terminals to the wheel with a console command?

Not sure about the sync command but probably you need a "link command" that doesn't exist. You spawn big wheel entity and terminals and random chairs but the game does not recognize them like you think terminal near chair = working betting terminal, terminals near big wheel = working big wheel... nope... you need either plugin to do this or use RustEdit to add working big wheel and terminals to your map at Outpost. Slot Machine on the other hand is 1 entity (object) and logic behind is implemented inside this 1 object so you can spawn one and will works without need to link anything to it.

I don't know how it's done, but I've seen the gambling wheel on custom maps, so it is definitely possible.