[3] In 1951, he was a leading full-forward in the VFA seconds, kicking 112 goals for the season,[4] and he made his senior debut for Port Melbourne in 1952.
Over the following twelve years, Bonnett was a prolific goalkicker for Port Melbourne, kicking a then-VFA record of 933 goals through his career, passing the previous mark of 880 goals set by Frank Seymour in the 1930s; as of 2014, he is the third-highest goalkicker in VFA history, behind only Fred Cook and Rino Pretto.
[6] He spent his entire senior career with Port Melbourne.
Bonnett retired from the seniors at the end of 1963, but continued playing as the captain-coach of the Port Melbourne Seconds team;[8] over the following three seasons, he kicked another 301 goals in the seconds.
[10] Bonnett's younger brother Barry also spent time at full forward at Port Melbourne after Bob's retirement.