Van Bommel completed a 6million euro (£4m) switch from Barcelona on Monday after agreeing a three-year contract with the Bavarian giants.
The Holland international will join Hargreaves in the engine room, with Bayern insisting the England midfielder will not be leaving the club despite the continued interest of Manchester United.
"We want to move forward with Mark and Owen," said Hoeness. "Our transfer activity is finally over.
"We are not a bank but a football team and we would be crazy to sign van Bommel as a replacement for Hargreaves."
Van Bommel is instead seen as a replacement for Michael Ballack, who moved to Chelsea in the summer.
Coach Felix Magath could not mask his delight after landing the 29-year-old from the Spanish champions.
"I am glad we have managed to buy such a player just before the transfer window closes," he said.
"He has international experience and can lead our relatively young team."
Van Bommel, who will link up with friend and former Holland Under-21 team-mate Roy Makaay at the Allianz Arena, is looking forward to the challenge ahead.
"This is a great day for me and I am proud to be able to wear the FC Bayern shirt and play here," he said.
"Obviously, Roy has told me a thing or two about FC Bayern, but I made the decision to come here.
"I want to score a lot of goals and really give it a go. I think Bayern can go places in Europe."
--------------
bon ben grosse deception ..
on aura pas de vrai millieu defensif cette année.