Bentham has a Master in Business Administration MBA, Bachelor in Arts (Maori and Education) and a Diploma in Teaching (Maori Immersion).
He is married to Kate Cherrington and father to Tuakoi and Tahuaroa. His tribal affiliations are to Tauranga Moana (Ngā Pōtiki, Ngāi Te Rangi, Ngāti Pūkenga, Ngāti Ranginui); Te Tauihu o Te Waka A Maui (Waikawa Picton, Nelson-Motueka, Wakatu) Te Arawa (Ngāti Te Roro o Te Rangi) and Ngai Tahu.
He worked for Te Wananga o Aotearoa for 20 years (1994-2013) and as Deputy CEO and CEO for his last 14 years. He chaired the WIPCE World Indigenous Peoples Conference in Education in New Zealand (2005) and was the Associate Director of Wakatu Incorporation (2005).