There will actually be 3 different "buildings" as a part of the VMC station. The one under construction in that image will be the VIVA bus station, which will look like an even larger version of the existing VIVA BRT stations, and will be located in the middle of Highway 7. There is then the main station entrance on the north side of Highway 7, which is nearing completion, then there will be a YRT bus terminal north of that, which I believe just started construction this summer.
The main station entrance is being built by the TTC, Metrolinx is building the VIVA station, and YRT is building the bus terminal. The legal ownership structure of VMC is quite possibly one of the most complicated in the country, especially once you include the fact that Calloway REIT owns all the development land around it, and is building commuter parking lots on their vacant lands to pull in some revenue.
YRT is also building a large bus terminal and something like 1,500 parking spaces at Pioneer Village Station in the Hydro One Corridor.. (more ownership issues there..)