home aquariums- not likely. However large public aquaria have reported frequent spawning events.
The biggest problem w/ tang spawning is they require large to huge amounts of space for the courtship/ascension. Home tanks just dont provide this, I saw a video from a private pet store w/ a 20,000 gal tank, who had blue tangs and yellow tangs spawning daily.
As for has anyone ever raised a blue tang spawn. there was a report out of the pan-pacific that they could raise these fish to quartersize juveniles.