Hi Pelle!
Really sorry for taking so long to reply.
About your question, the unofficial spritekit runtimes still need a lot of improvements. If you decide to work with spine and sprite kit, you have to consider that you will have a LOT of restrictions when creating the animation on spine editor.
If you are starting your app from scratch, you may consider using another engine like unity or cocos2d. Their runtimes are way better developed.
In our case, we already had the app up and running on native iOS, so using cocos2d for example would mean re-coding everything. So we preferred to use the spritekit runtime and deal with the limitations.
Cheers!
Hugo