Configuring for a Stereo, a 5.1 and a 7.1 mix

Question

I have a title that is already finished in stereo. We are moving to PS4 and I need to create a 5.1 and a 7.1 mix. I have worked with surround before, but not in Wwise or in a video game. Are there any best practices or tutorials regarding how to handle the outputs in Wwise? Do I have one audio bus for each surround channel configuration alongside a stereo one? Do I just add the Surround busses to the current stereo setup? Any advice or guidance on this is very much appreciated.

This is a Wwise - Unreal 3 - PS4 build

Tom Todia