What they said, but here are some of the relevant areas from the Qantas T&C's :
13.3 Award Flights - Booking Conditions for all Award Flights
13.3.7 Award Flights are not available on Codeshare Flights unless otherwise specified by Qantas. Award Flights must be booked using the airline designator of the operating carrier unless otherwise specified by Qantas
15. Flight Upgrades
Until 24 May 2005:
15.1 General
15.1.2 A Flight Upgrade may only be requested on a paid, confirmed and ticketed Qantas domestic or international flight booking on a service operated by, or on behalf of, Qantas, with a Qantas flight number. Flight Upgrades are not available on Codeshare Flights. Flight Upgrades are subject to capacity controls and availability is limited.
You can pay onboard for an upgrade from WHY to WT+ (IIRC GBP250 and upwards), however you won't receive points and SC's for the upgraded class.