The Congo international had been struggling to secure a regular starting berth at Molineux since joining from French side Reims in August 2016.
Oniangue made 11 appearances for Wolves in the early stages of the 2016-17 season and scored twice before joining Bastia for the remainder of the campaign.
The 29-year-old was then loaned out to Angers in January 2018, where he played 15 times and scored once.
"I would like to thank Wolves for allowing me to discover English football," Oniangue wrote on Instagram.
"Thanks to the fans who were absolutely wonderful with an amazing atmosphere. I wish good luck and a good season to all involved at Wolves."
Wolves will be playing in the Premier League next season after winning the Championship title last term.