It doesn't care about the software. What it is doing is instead of paging out to disk when out of RAM, it instead compresses that data to create more free space. So it only comes into play if you don't have sufficient RAM to begin with. It's always better to have enough RAM rather than rely on paging.
However: 8GB is probably enough (what components of Adobe CS are you using and how are you using them?)
However (2): You can't add additional RAM later, so when in doubt, buy it now.