I read the man page, but I didn't see the answer to your question in there.
I am assuming that it would only dump the root filesystem in your example. Other mounted filesystems like /home or /media, if they're separate filesystems, probably aren't included. You'd have to run a separate dump for each one.
Best option to find out is to try it and see what happens. No better way to learn than by doing.
emphasis mine
How do you interpret that?