Bontoux made his debut at the Opéra Garnier in Rameau's Hippolyte et Aricie, in which he interpreted the Third Fate, under the baton of William Christie.
He was a soloist in the Requiems by Liszt (recorded in 1989 under the direction of Yves Parmentier),[4] Verdi, Fauré, Mozart (Bertrand de Billy conducting), and Cimarosa (recorded in 1995); Bach's Christ lag in Todesbanden and St John Passion; Haydn's The Seven Last Words of Christ (Valérie Fayet conducting); Mozart's Great Mass in C minor, K. 427, Vesperae solennes de confessore, and Coronation Mass; Rossini's Stabat Mater; Dvořák's Te Deum and Mass in D major; Beethoven's Choral Fantasy and Symphony No.
He also performed Bartolo in The Marriage of Figaro; the tree and the armchair in Ravel's L'enfant et les sortilèges (under the baton of Manuel Rosenthal); the step-father in Milhaud's Le pauvre matelot (under the direction of Jean-Sébastien Bereau);[5] Banquo in Verdi's Macbeth (under the baton of Claude Schnitzler at the Saint-Céré festival in 1992).
In 2002, he also sang the role of Antinoo in Monteverdi's Il ritorno d'Ulisse in patria under the direction of W. Christie.
Staged in 2000, as part of the Aix-en-Provence Festival, by Adrian Noble, this opera was the subject of a major tour from February to June 2002 (Paris, Lausanne, New York, London, and Vienna).