Actually, there are 3 favorite teams to win the UCL trophy. We have Bayern Munich besides Man City and Real Madrid. We don't forget that Bayern Munich is also a strong team and they often has a good history in UCL. It is very unfortunate that among these teams, 2 of them must fight in the current round. People expect that those 3 teams will be in the semi-final round at least.
Bayern Munich, this season is completely in shambles. I don't even think they will go past Arsenal if the form turns up on a good day. Real Madrid has to tussle it out with Manchester City, whoever wins in that match is most likely reaching the final and probably winning this year's title.
I agree with you that whoever wins in that match can end up winning the UEFA Champions League trophy this season. In the past two years in the UEFA Champions League, anyone who wins in Real Madrid vs Manchester City match always ends up winning the UEFA Champions League trophy that season. Let's wait and see if history will repeat itself.