Wendt's television career began as a news presenter for ATV-10 evening news. She then went on to be one of the first reporters on the Australian Nine Network's version of 60 Minutes, as well as filing stories for the American CBS 60 Minutes.
Wendt won the 1992 Gold Logie Award for her role as host of A Current Affair. She was not at the presentation to accept her award, citing commitments to A Current Affair, based in Sydney, while the awards were being presented in Melbourne. While it is unusual for a Gold Logie recipient to not personally accept the award, despite media reports at the time she is not the first to have done so. (Variety performer Lorrae Desmond was not present to accept her Gold Logie in 1962 as she was overseas at the time.)
Rumours of her departure from Nine began in June 2006, when the network announced it would merge its Sunday and Business Sunday programs. Leaks to the print media, reportedly from high levels within Nine and described by journalists as "ham-fisted", revealed that the network wanted to replace Wendt with Ellen Fanning. Then CEO Eddie McGuire in particular was accused of trying to "white-ant" Wendt. On 1 September 2006 it was announced  that Wendt would leave the Nine Network. News reports suggested she would receive a payout of more than A$2 million in lieu of the remaining 2½ years of her contract.
The absence of Wendt on the Sunday program's relaunch on 3 September 2006 was met with an unprecedented number of complaints that flooded the Nine Network's switchboard and of which the operator failed to keep count.
Wendt was then sacked from her regular "Lunch" column for The Bulletin magazine, due to the association the magazine has with the Nine Network; both had the same parent company, PBL.
On 12 September 2006, just ten days after she left the Nine Network, Wendt agreed to appear on stage at the Seven Network's 50 Years of Television presentation, where she co-presented the News and Current Affairs section with Sydney news presenter, Ian Ross.