I wasn't able to find an answer in here, so will go ahead and ask in case anyone has any experience. RJ flights booked into D CMB-DOH-AMM-FCO. CMB-DOH-AMM is on QR (RJ codeshare) with DOH-AMM being in QR "F" AIUI. Given it's ticketed in D, it's not clear if I will have access. I will of course try and report back, but I had read that it needed to be ticketed in F (which BA / QR will do on those and people have confirmed access), which an RJ codeshare in D is not.