Boateng said that it was not easy to go to the Etihad and win, but that the result showed how successful Pep Guardiola's time at the club could be.
"We had a great game today, we looked very strong," he told UEFA.com. "It is not easy to win here, 3-1 against a big club, so we can be happy.
"After last year of course it is difficult but we want to do better, we have a new coach and he gave us a lot of confidence as you could see in the game. The coach has good tactics for us, we're confident; everybody likes the ball and to play football."
Bayern currently top Group D with two wins from two.