Hi,
I' reached the craftman class finishing my masterpiece, and after that the guildmaster said that to me...
BUT now i have the answer !!!
That's because my relationship with the town was bad (-3). After a few works with the guild, it was +1, then the guildmaster said Ok !
BUT now and other thing goes wrong...

he only propose me to open winery (and finaly not because this business makes no profit).
I've paid 75 gold to learn that the brewery business is ok (615 profit),so why doens't he propose that to me ?