Political Memes

I think that the important perspective here is the phase of the land grab operation and the perceived statelessness of Syria. When Russian troops walked into Crimea the press wasn't ready to call it an outright invasion and it certainly didn't feel like one. Syria currently is not in the situation of enforcing their territorial integrity and the military strikes at military targets in Syria have some kind of international legitimation, independent of if those are valid. Same goes for Turkey. So while it would be appropriate to call out Israel and Turkey for their opportunistic raids into Syria, I can see while the press struggles to name it appropriately. Again, not because it's right, but because the circumstances are favorable to remain cautious about the language.

Right now one is heavily speculatory and based on ongoing and disputed events (ie the fact that Israel and its allies will lie through their teeth, same as Russia did, about their intentions until the last moment); the other was a pretty firm event quite literally being acknowledged by the perpetrator. Not only that, but outright annexation is not definitely the intention of Israel - it may be that they want more territory to engage in 'frozen conflict' style 'diplomacy', the same as Russia did with the Donbass for nearly a decade.

For most news sources, it would be reasonable to speculate that there's a strong pro-Israel bias. AP is generally pretty aggressively anodyne, though. If there's a pro-Israel bias, it's likely not a strong one.