The British English adjective "wonky" means unstable or wobbly. Probably no connection. The Australian noun "wanker" means one who masturbates, from the verb "to wank." Probably no connection. An older British usage of "wonk" referred to a recruit seaman who was unreliable in that he had not yet acquired knowledge or skill. Probably no connection, save that both usages are derisive. The earliest American usage probably meant bookish or studious. OED says its been around since 1962. Webster claims a use in 1954. The term evolved to mean someone with remarkable expertise in a very narrow field. Erich Segal used it in "Love Story" in 1970, to wit: "Who could Jenny be talking to that was worth appropriating moments set aside for a date with me? Some musical wonk?". I think it has lost nuance and come to mean "nerd."
