For the $15 prepaid plan, the 25 cents a minute rate would be additional to the $15 plan price. The $15 covers unlimited texting and unlimited WiFi access at all MTS WiFi hotspot locations. To make any calls with this plan, you would need to add additional money to the plan to cover the 25 cents a minute rate for calling within Manitoba, or the 50 cents a minute for Long distance calling.
I do apologize for the incorrect information that I provided before. I hope this clarifies your initial question and updates my message correctly to provide you better information.