In the 2000–01 season, Bollmann was transferred from SpVgg Beckum to SC Paderborn 07. With his club, he was promoted to the 2. Bundesliga. Later in the summer of 2006, he joined Arminia Bielefeld. After a period of settling in, he was regularly capped in the second half of the 2006–07 season, with the result that in May 2009 his contract was prolonged to 2012.
Bollmann is married to his wife Kristina. In 2008, their common son was born. His brother Maik Bollmann (*1991) plays for the Hammer SpVg in the Oberliga Westfalen.