Nonyane recently became a free agent after Golden Arrows opted against extending his two-year contract following an injury-affected stay with Abafana Bes'thende.
Mere, meanwhile, spent close to seven years with Platinum Stars before seeking greener pastures following the club's relegation to the National First Division and relocation to Cape Town at the end of 2017/18.
The duo started training with Wits on Monday and are currently in Durban for the club's pre-season camp. Gavin Hunt's men are scheduled to play a friendly with NFD side Uthongathi FC at SJ Smith Stadium today.
"I can say things are looking good for Nonyane at Wits and he's part of the Wits side that is in the pre-season camp in Durban," a source tells this website.
The Clever Boys have signed Bantu Mzwakali, Gift Motupa, Robyn Johannes, Deon Hotto and Brighton Mhlongo ahead of the new campaign.