Bono's performance didn't seem good in the club and you shall also remember if bayern needs a goal keeper that has a very good performance with the club.
I think you are right, at club level Yasin Bounou is not very good and so far Yasin Bounou has conceded a lot of goals at Sevilla in the last 14 games. He is more than 30 years old and is considered by Bayern Munich, and it looks like that will make the transfer impossible. Yasin Bounou had some good magic during the World Cup but I don't think it will ever be the same at club level. Several teams might be ready to sign him from Seville, but not Bayern Munich.
Sven Ulreich should be the goalkeeper who will get many chances at Bayern Munich if Manuel Neuer is injured or no longer gets a contract extension. But considering Sven Ulreich's age, which is already 34 years old, it is important to get a goalkeeper who is the younger of the two.