It is much harder to check what Time Machine has backed up.. you can assume that everything currently needed to reproduce the same setup on another computer is there.
To double check you must spend a bit of time understanding both how Time Machine works and how to restore from it.
Read up a bit from Pondini's excellent KnowledgeBase of articles.
http://pondini.org/TM/FAQ.html
Q7-9 are highly relevant.
Also go back to the main page and read the main articles on how TM works.
I must also say at the moment, on Yosemite in particular, I would not fully trust Time Machine.
I encourage people to make a bootable clone using Carbon Copy Cloner for example to a USB drive. You do not need to do it continually but the clone makes for a much easier return to normal.. since you can simply change boot disks. It costs $40 and is excellent value.. there are others you can buy.. and I am not connected to CCC in any way.. other than I use it and been amazed at what a great piece of software it is.