To me bloom is the same as harmonic richness. Bloom is not fat or warm per se. It is a highly complex (due to overtones) sound with texture. "Air" is the surrounding and expanding sound we generally don't hear in real life. I think air is an artifact of microphones. "Air" is not: ambient clues --> the diffuse reflected sound by hall acoustics and nearby structures. "Air" that appears like an "aura" is totally wrong! We don't hear such a thing in real life. You can hear this "aura" like phenomenon with the older Jadis units for example. Like Dave said: it is pretty but not very realistic (although some people are addicted to this "aura").
Chris
Chris