I skipped the yeoman ceremony and after getting enough honor for the acolyte ceremony I built a throneroom, but I still can't accept the quest because I apperantly don't have a good enough throneroom. When I press on the throne it tells me it is good enough for a knight. My only guess is that because the pawn isn't a yeoman I can't assign him to the throne and so the game believes there isn't a valid throneroom.