The promo page at
Frequent Flyer - Program - Double Status Credits defines an eligible flight as
* An eligible flight for the purposes of this promotion means any flight with a QF flight number on the ticket where Status credits are normally earned. Status credits may not be earned on some fare types and booking classes including Classic Award flights and Qantas codeshare flights (i.e. with a QF flight number on the ticket) operated by Jetstar or Jetstar Asia other than in Economy booking classes Y, B, H, K, and L (when booked as part of a oneworld fare). Qantas Segments booked in X, U, Z or P classes are eligible to earn Points and Status credits only when booked as part of a Qantas & Jetstar Any Seat Award. For details visit
qantas.com.
The important bit being
Qantas Segments booked in X, U, Z or P classes are eligible to earn Points and Status credits only when booked as part of a Qantas & Jetstar Any Seat Award.