To answer the question, Audio Master technology is best HEARD when used on Audio recordings, however it does have the same benefits when doing data recordings. The quality of the recording is increased because of the wider lands and pits of the discs.
While I personally can't say that I've tested the VCD function with Audio Master, I have done many data CDs in this mode (even with the CRW3200 series).
I hope this answers your questions.
Multimedia Products Division
Yamaha Electronics Corp.