Born in Aschaffenburg, Bommer played 417 games between 1976 and 1996 for Fortuna Düsseldorf, Bayer Uerdingen and Eintracht Frankfurt in the Bundesliga. Bommer scored 54 goals in the German top flight. He played for West Germany at the Euro 84 in France.
Bommer started his coaching career with the reserve team of Eintracht Frankfurt between July 1994 and August 1995.
After stops at VfR Mannheim where he was head coach between July 1997 and April 1998. Bommer then moved on to Viktoria Aschaffenburg where he was head coach from July 1998 to June 2000.
Bommer left and became head coach of 1860 München in July 2004. His tenure ended in December 2004.
Winning five of his 15 league matches in charge.
Bommer"s next job was as head coach of 1. Football Club Saarbrücken. He was there between August 2005 and May 2006. Bommer then went to MSV Duisburg between July 2006 and November 2008.
Finishing with a league record of 28 wins, 21 draws, and 31 losses.
Bommer returned to Wacker Burghausen in July 2011 and was there until December 2011. He then joined Energie Cottbus the next month and was there until November 2013.
In October 2015 he became the new coach of Regionalliga Bayern club Viktoria Aschaffenburg, replacing the sacked Slobodan Komljenović. As of 21 October 2015.