Some general questions regarding trellis

Around 4 or 5 months ago when the lead developer left, I inherited 5 sites that use the set up for development. I have most of the basics down, updating dependencies, updating, deploying, making changes in the sage-based theme, deploying those, etc.

What I did not get to cover before he left was how to properly update trellis, bedrock, sage. When the trellis update was released, I thought I had updated it correctly, even in my github repo, it says that I am on version rc.2, however when I run a deployment it comes up as rc.1.

Is there an easy way to actually see what version of trellis is on my local Ubuntu machine, and is there a fairly simple way to go about updating trellis the correct way?

Are the trellis files currently in used cloned from github trellis repository or
just the files without version control (.git folder)?
In either case, it should be possible to find out the trellis release by looking into the file.

For my own part, I prefer the whole trellis repository cloned with a separate branch to
which I regularly merge upstream changes from master branch.