Bayern Chief Executive Karl-Heinz Rummenigge has questioned City's free-spending ways in view of impending financial fair play rules and has cited the club as an example when calling on UEFA to impose strict penalties on those who do not comply.
"I don't understand Rummenigge's behaviour against Manchester City - he's been talking about us for six months," Mancini told a news conference on Tuesday.
"Every time [it is about] financial fair play, he continues to say he hopes Napoli go through to the second stage... I don't understand what's happened with Rummenigge, tomorrow I want to ask him."
The new wealth at City was in evidence at their Carrington training ground where a posh department store has set up a pop-up shop where players can do their Christmas shopping.
Bayern coach Jupp Heyckes denied there was any ill feeling from his club towards the world's richest football club.
"I don't know about all that [Rummenigge's comments]... we have got respect for Manchester City, just look at what they are doing in the English league," he told a news conference.
"There is no resentment, it's more about two teams fighting each other in competition on a sporting level."
City need to beat group winners Bayern at the Etihad Stadium on Wednesday and hope second-placed Napoli fail to win at Villarreal, who have yet to pick up a point, in order to qualify for the last 16.
It is not just Rummenigge who has spoken unfavourably about the Premier League club with Napoli President Aurelio de Laurentiis taunting them last month by saying City owner Sheikh Mansour would "buy another toy" if they are not successful.
"He [De Laurentiis] doesn't know him," Mancini said of the club's owner. "Sheikh Mansour is a very good man... I can't think about this stupid situation."
Having once been dismissed as "noisy neighbours" by champions Manchester United, City are finding the racket is about them and they feel they have the quality on the pitch to match it.
BIG PROBLEM
Mancini, who has rated his team's chances of reaching the knockout stage of Europe's elite club competition at 30 percent, thinks there will be a lot of sides who will be relieved if City do not progress.
"Bayern think this," he said.
"If we go through it will be a big problem for the other teams... I think that every team is worried regarding Manchester City because Manchester City in the future will become one of the top clubs in the world."
One player who is not part of that vision is striker Carlos Tevez, who is in Argentina without the club's permission after refusing to warm-up in September's match against Bayern in Germany.
AC Milan have spoken of their interest in signing him on loan but City are only prepared to sell him.
"I think that for us it is important to sell him. We can do this for him and for the club," Mancini said. "If he has the chance to go to Italy, I am happy for him."
It is not just outsiders who have been talking about City with defender Kolo Toure under the media spotlight for comments he made to a French magazine this week saying he had been victimised for playing in the African Nations Cup two years ago.
Toure has seen little first-team action since his return from a doping ban earlier this year but Mancini said the Ivorian was still part of his plans.
The manager said he was not going to investigate the article as he believed Toure's explanation that he had been misquoted.
