Royal Hong Kong Yacht Club
Bonnar was a staunch churchgoer and was one of the trustees of the Peak Church. He was also a prominent Freemason. He was also a prominent member of the Royal Hong Kong Yacht Club and of the St. Andrew's Society, being the president in 1913 and 1914 and member of the general committee at the time he died. Bonnar was also president of the Hong Kong Football Club.