If ur referring to sphere that are used in the grid (Teleport Sphere), then yes, u can only teleport to a certain node (a node that u have activated, or izzit nodes that other character have activated?) ONCE. That means that if u wanna return back to u'r original location, u need to use the teleport sphere again.

If u'r referring to the save sphere, then no u can teleport back and forth from ur current location to the airship like there's no tomorrow.