FYI, I redeemed an award ticket online via Qantas for a flight from HKG-TPE-NRT with the first segment on CX and the second on GK (Jetstar Japan). Qantas sold me this ticket with a 65 minute connection in TPE. When I went to check in at HKG, CX said that there is no way I can make the connection as they do not have a baggage interline agreement with GK and that I would have to clear customs and immigration in TPE. Since it was a QF ticket, I had to contact QF, which I did, and who were utterly useless. They refused to change the ticket as it was < 24 hours to departure (I was at the airport!) and said there was no award space anyway on an earlier flight. Basically, they said I was out of luck and had to fend for myself. Fortunately, the CX F check in agents were extremely helpful and friendly and managed to sort the situation out by liaising with QF ground staff and CX staff to get an award seat on an earlier flight and for QF to re-issue the ticket. Kudos to CX who resolved the issue when it wasn't even their problem. They got me on an earlier flight and I made the connection in TPE.
So a word of warning when redeeming CX and Jetstar flights in one ticket - QF will sell you an illegal itinerary, so make sure there is plenty of time for connections if you have baggage.
So a word of warning when redeeming CX and Jetstar flights in one ticket - QF will sell you an illegal itinerary, so make sure there is plenty of time for connections if you have baggage.