Ambient music is really such an "open" term, difficult to pin down. Whether it's "soundscape", "drone", "atmospheric"; it all fits the general "ambient" genre. Kind of like trying to describe one kind of music as "progressive". John Cage's "4:33" can be described as "ambient" because it is about listening to the ambient sound of the room and audience in the room rather than the person sitting at the piano doing nothing for 4 minutes and 33 seconds.
Interesting stuff, I like it quite a bit. Although I've only just recently heard it I can already say that its great ambient music to listen to while reading or while drifting slowly into slumber. Great work.