In 1833, Bennett lent support in absentia to the founding of what became the Royal Entomological Society of London. Bennett was awarded the honorary gold medal of the Royal College of Surgeons in recognition of his contributions to zoological science. Bennett went to Australia again in 1836 and established a successful practice as a physician at Sydney. However he kept up his general interest in science, and acted as honorary secretary of the Australian Museum which had just been established. He compiled "A Catalogue of the Specimens of Natural History and Miscellaneous Curiosities" deposited in the Australian Museum which was published in 1837. In 1860 he brought out his "Gatherings of a Naturalist in Australasia". He kept up a correspondence with his early friend Sir Richard Owen, to whom he had sent the first specimens of the Nautilus to arrive in England, and with Darwin and other scientists of the time. He was much interested in the Sydney Botanic Gardens and the Acclimatization Society, and was a vice-president of the Zoological Society, and a member of the board of the Australian Museum.