Jonas was a founding member of The Conspiracy Network, a theatre troupe who made their debut at the 1996 Winnipeg Fringe Festival (the second largest fringe festival in the world) with In Vitro Stimulation or The Great Canadian Way. Jonas co-produced, co-wrote and acted in the company's four productions between 1996 and 1999.
In January 2009, Jonas played Biff Loman in WJT's production of Death of a Salesman opposite the great Ron Lea (This is Wonderland, Street Legal) as Willy. The show was a smash hit for WJT, selling out 92% of it's run and garnering rave reviews across the board. In 2008, Jonas performed in WJT's acclaimed production of David Mamet's Speed-The-Plow, playing the sleazy and ambitious Hollywood producer Charlie Fox. In October 2002, Jonas starred in a stage adaptation of Chaim Potok's famed novel The Chosen, also presented by WJT, in his home city. In the two years prior, he appeared in a number of theatrical productions in Toronto, including the world premiere of Incompletance at the Buddies in Bad Times Theatre. In March 2000, Jonas performed in the world premiere of Daniel Libman's Cote Saint Joe, a co-production between Saskatoon's Persephone Theatre and WJT. The play was directed by Richard Rose (Necessary Angel, Stratford) who is now the Artistic Director of Toronto's prestigious Tarragon Theatre.