If you would like to make a backup of the team project to a local drive, the best way to do this is through Edit // Team project // Convert Team Project to Project. You can save a local premiere pro project this way.
Just to expand on this question a bit further and I have had a ton of coffee, you might want to take a look at the media browser. Within the media browser, we do save versions of the team project with every share that you, or another user performs.
To take a look at this --
1) Go to your Media Browser window,
2) Select the creative cloud // team project versions (make sure you have the version tab selected)
3) Select your team project that you are working on.
4) Look at the slider on the right hand side, this is a record of all the shares being perfomed. From here, you can create new team projects from previous versions.
There is a lot of things you can do here. Like drag and drop a previous version of the timeline to a new project. It will also grab all associated media with that timeline to the new project.
Hope this is helpful.
Nate