Grab the original (but empty) wine bottle. Order a $20 bottle of red and grab a new table. Pour cheap wine into glasses on new table, dispose of (now empty) cheap wine bottle and place expensive wine bottle on table. Thank dad for the wine and be sure to tell him how good it is. There's a 99% chance he won't notice the switch and will be happy to have provided you all with such a quality drop.
Nb If this is in NSW and you accuse the other couple of stealing your wine, they will first be unable to recall it, then deny all possibility of having even being in the same room as the wine, but if you look really carefully through the waiters pockets you will probably find a hand written not thanking him for providing such a notable bottle.
None of this happened in reality.
It's a short movie script for a friend... some of the details have been changed; the actual scripts is more detailed and specific, but he's having trouble completing the scene.
He wants realistic drama.
My reaction was to grab the handbag and demand compensation in a very confrontational manner; upturn table even... but I like the replace with cheap wine approach.