1) AI planes will more often head for my CVs (which is the smart thing to do) while my own will get distracted by low value targets such as convoys and any other floating piece of junk
2) AI planes and ships do more damage than mine (a point and case is that the AI consistantly sinks more ships in Hawai than I do even though I send more CVs there... other examples include my beautiful US CVs being sunk by a lone torpedo bomber)
I've seen my torpedo bombers destroy Japanese CVs in one pass with no previous damage and vice versa. I've also seen the AI be distracted by convoys/amphibs reasonably often. I haven't noticed any sort of AI bias. The Japanese planes being superior earlier on is very noticeable, though.
The allied planes being superior late in the war is obvious too. After 1943 the allied planes start destroying japanese ships like they are made of cardboard.