[2][3] After doing articles at the solicitors firm Gair & Brahe, he was admitted to practice in the Supreme Court of Victoria on 1 May 1931 and called to the Victorian Bar on 30 July 1931.

[5] He was subsequently promoted to temporary squadron leader on 12 February 1940,[6] to wing commander on 1 October 1941, and to group captain a month later, when he was appointed Director of Personnel Services.

Following the end of the Second World War, Winneke left the RAAF returned to practice at the Victorian Bar.

[12] As Solicitor-General he regularly prosecuted in important Criminal trials, and also appeared for the State of Victoria in Constitutional cases in the High Court of Australia and the Privy Council.

While Solicitor-General, he provided advice to the Victorian Government but could be swayed by political considerations as outlined in an ABC News article of 24 April 2021 The memo that erased a scandal.

In 1962 he appeared for the government in the High Court, opposing any further delay to the execution of Robert Tait, who had been convicted of murder.