Career
Bonanni started his career at Associate of Science Roma youth system. He spent on loan to Viterbese, Panachaiki and Vicenza. Vicenza bought half of the player registration rights for €200,000 after a season long loan.
On 27 June 2005, he was bought back by Roma, for €500,000, and sold to Palermo on 1 July 2005, for €750,000 (the fee of signing Cesare Bovo on loan).
He made his Serie A debut against Parma F.C. on 28 August 2005. University College Sampdoria acquired half of the player registration rights on 14 July 2006, for €2 million, along with Christian Terlizzi (50% for €15 million), as part of the Aimo Diana"s transfer (€5M).
He played 7 games in Serie A and 4 in Coppa Italia for Sampdoria, before loaned to Ascoli on 12 January 2007. On 17 August 2007, Bonanni is on a one year loan to Bari of Serie B. He returned to Genoa, but after played once in 2008-2009 season, he left for Grosseto of Serie B. In June 2009 Palermo gave up the remain 50% registration rights to Sampdoria
On 31 July 2009, he signed a 3-year contract with Pescara of Prima Divisione for free.
On 12 July 2011, he signed a two-year contract with Swiss Challenge League side Football Club Lugano on free transfer.
On 6 April 2012 he returned to Italy for Lugano"s sister club Genoa (effective on 1 July 2012), however the sole purpose was transferred €1.45 million "transfer fee" to Lugano. He left for Serie B club United States. Grosseto F.C. on 31 August 2012 but returned to Switzerland on 9 January 2013, in temporary deal from Genoa.