I could be wrong but I don't think anyone can yet predict exactly when (or even if?) Season 2 will be "free" for Prime subscribers.  

I'd suggest contacting Amazon to ask if they have any available information on that.

I wanna watch right now, so I'm buying a season pass  (not from Amazon).

@lantzn said:

I'm fairly new to Amazon Prime and recently watched season 1. Does anyone know the release schedule of tv shows on AP? I'm anxiously waiting for season two.

Not sure about prime, but you can watch all the new episodes on Syfy.com. There is even a SyFy add-on for Kodi that lets you stream in 1080