The French Football League postponed Lyon's match against Monaco at the former's request on Thursday.
The game, which was scheduled to be played on April 24 between the first and second legs of the semi-final will now be played on May 12.
Lyon wanted more time to prepare for the return leg.
"I will ask our sports director Christian Nerlinger to demand from (European football's governing body) UEFA to reverse the French league match postponement," Bayern coach Louis van Gaal told Friday's edition of Munich's tz newspaper.
"The French federation thinks they can give Lyon with this decision a better chance of reaching the final and I think they are right. But UEFA must monitor such things because this not fair play anymore."
Lyon face Bayern in Munich on April 21 before hosting the German club at their Gerland stadium on April 27.
While Lyon now have a free weekend ahead of the return leg, Bayern must visit Borussia Moenchengladbach on April 24 in the Bundesliga.
Van Gaal, who is in his first season at the Munich club, said he wanted both teams to have the same amount of rest.
"If UEFA are organising competitions then they must make sure the same conditions apply for everyone," said the Dutchman, whose team are also chasing a domestic league and Cup double.
"It is clear that it is not possible that all play (their league matches) on the same day but postponing a game is a completely different matter. It should not happen," he said.
Bayern have reached their first Champions League semi-final since winning European football's leading prize in 2001.
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