Bennison grew up in Western Australia in several family settings, his mother having been killed when he was five years old. Bennison was convicted twice of armed robbery and served two terms in gaol. On the second occasion he attended creative writing workshops delivered by Lockie McDonald and was inspired, with two other inmates, to form the writing group SALT (Silenced Authors, Lavish Tales). In 2002 the group won an Australia Council grant to develop their playwriting.
After his release from gaol, Bennison furthered his poetry and playwriting skills and gained an acting role in Smoke at the 2003 Melbourne Fringe Festival.