I think its fine to use never had a problem with it before but if you are looking for the best finish for putting up tiles then make sure he has made the bonding very flat! I like the wall with a smooth finish. I get them plastered if I was you gives you a bit more time with the adhesive. Bonding seems to suck any life out of the adhesive very fast. So if your not to clever you could end up rushing to stick the tiles, After spending most of the wall with tile adhesive and finding they wont stay up as it's gone off to soon.
Christ what a long answer! End of the day get the walls plastered for a beeter job. And remember Mool Your paying him to do what you want, So if your not happy dont use him.
Good Luck and sorry about the long answer.
Bobby