Yes, the oil in a wet clutch will transmit power, particularly when cold.
Dry clutches will too. There is always enough touching inside the clutch to spin the rear wheel while in gear with the engine running and the tire raised off of the ground. But you should be able to stop the spinning by just touching the tire. I've been known to occasionally spray chain lube on under such circumstances, since it's not all jerky like if the clutch is out. "Don't try this at home."