Bonnaire made his international debut for France in a match against Scotland on 21 March 2004 during the 2004 Six Nations Championship, as a replacement. He earned a further two caps for France that year, in tests against Australia and the All Blacks. The following year he was in the starting lineup for France in all five of their 2005 Six Nations Championship matches as well as the June/July tests against the South African Springboks and Australia. He scored his first try during the 18 June test against the Springboks.
He received another three test caps in November of that year. The following year he again played in every match at the 2006 Six Nations Championship, which France eventually won.