Greyhound was down to one to two trips per day between Brandon and Winnipeg depending on the season. Already competing with them for years has been Brandon Air Shuttle. While it is more expensive, a shared taxi van picks you up/drops you off at your home in Brandon and uses the hotel shuttle area at YWG. Depending on the season they make 3-4 trips per day. While higher end than Greyhound, perhaps they pick up some of the slack.
http://www.brandonairshuttle.com/