of course he'll say that to try and put his client into a favourable position when it come to negotiations. some of it might be true, some of it will be a bluff.
think Yaya would accept a 1 year extension on the same wages or a reduced wage. I doubt any 'so called bigger clubs' would offer money more and a longer contract than that. And judging the way he let Jesus take the penalty the other night without making a fuss, showed he cared about Jesus' development and confidence to help the club move forward, a thought that he wants to still be involved in that process.
Think Bayern wanting him is wishful thinking. At best he would be a squad player on significantly reduced wages as they don't need 'big names' and tend to buy young players now with years to develop and improve.
The 'offers on the table' are probably from clubs like Valencia, Sevilla, Inter etc that want that experience as they try to progress in Europe.