Recruited from Rosebud and the Dandenong Stingrays, he was placed on the Port Adelaide's rookie list but was upgraded to the senior list during 2006.
Bentley played his first AFL game on 12 August 2006 against the Western Bulldogs in Darwin and kicked his first AFL goal with his first kick.
He was allocated to Sturt in the South Australian National Football League (SANFL) when not selected for Port Adelaide.
Bentley was delisted by Port Adelaide at the end of 2008 after twenty-one games with the club.
Bentley made a return to local football in 2010 returning to his old home club, Rosebud, in the Mornington Peninsula Nepean Football League, and in 2011 he was the joint-winner of the George Osborne Medal as the Nepean division best and fairest.