Yes, your virtual machines
can be a part of your Time Machine backup ... but you probably
don't want to have it that way.
Normally you will add an entry to the Time Machine "Options" to exclude your virtual machine folder. The reason for this is that the
VM file is really big (usually 30GB or so on mine) and it
changes every time you use it. This causes TM to add a 30GB backup each hour as an incremental backup.
I usually allow TM to include my VMs on the
first total backup (so they will be there if I have to do a full restore) and then exclude it from then on. I then handle the backup of the VirtualMachine folder either manually, with a backup utility app, or with a scheduled task script.
I don't store any important data within the VM (I use Quicken for Windows) and direct the datafile to a shared Mac directory (or use DropBox).
Your BootCamp installation will not be part of the Time Machine backup. You will have to do that separately (perhaps use the built in Windows backup). You could probably use a common external backup disk partitioned part as OS X and part as NTFS.
-howard