Hi all. Just had a similar experience.
I'm a PC member and redeemed points for a SYD to JFK Y flight (all on QF 3 and 4, so no other airlines involved).
Received 52 SC for the inbound flight (JFK to SYD) but nothing for the outbound flight (SYD to JFK).
Upon enquiry, I was told that X class was not eligible for SC i.e. I wasn't even entitled to the 52 SC in the first place !
I was referred to
https://www.qantas.com/au/en/freque...rning-tables/earn-category-tables.html#qantas.
I was then told that since X does not appear, no SC are eligible at all !
Does anybody know if I should be entitled to SC on the outbound flight ?