Gulf Air are operating the ex-SQ A340-300's on the SYD-SIN-BAH route and these come equipped with PTV's in Y class. So I dare say you will get PTV's on your flight. Also all A330s are PTV equipped in all classes.
Okay reconfirmed above info is correct ( I happenned to be on GULF Site checking out the Grand Prix packages while browsing Airliners also)
Picked from their website-
As for economy class, passengers can enjoy a channel that has been designed to feature a cross-section of entertainment and informative programmes. The selected programme is shown on the main screen. However, on our A330 aircraft, passengers have their individual crystal screens that are fixed at the back of the seats in front of them.