So you want to use Unity Collaborate and share a project with other users who don't own Playmaker?
I haven't tried Unity Collaborate yet, but Playmaker should work fine with it.
However, not sharing Playmaker with other users who don't own a license is trickier. There may be a way to do this if Collaborate offers some way to exclude files for sharing. But the project would have errors for anyone who doesn't own Playmaker to import. I'd need to do some research to figure it out... it seems like this would be a common problem with assets in Collaborate projects!
The easiest (but not cheapest) solution is for all users to have Playmaker licenses