Upgrades are never guaranteed. Some airfares do no allow upgrades with ff miles/points/avios. Or for some even with cash.
Getting 2 upgrades on the same flight is a magnitude harder.
Generally you can only upgrade a flight the marketed and operated by the airline of your ffp. With some exceptions.

But Star Alliance has a cross upgrade scheme, but requires a high priced base fare and has onerous t&c's. Extremely unlikely an airfare via cruse line would be eligible. TK is in Star Alliance.
UA thread --> How to upgrade with UA miles on Star Alliance carriers Are others in different forums.

And AA also has a cross airline scheme with BA & IB. But again has onerous t&c's.
Many threads in the AA forum about upgrades.
https://www.flyertalk.com/forum/amer...advantage-733/