I know that a spotlight query is capable of reading the "Artist" ID3 tag of mp3 files but is it also possible to read out (speak) the "Artist Album" ID3 field? This source doesnt say anything about it?
It isn't possible. You can check to see the metadata associated with a file by using the
mdls ~/Music/iTunes/iTunes\ Media/Music/Artist/Album/Song.mp3
Try it with a song that has an Album Artist and you unfortunately won't see it in the output.