Having the bunk bed above the room, gives it the feeling of nesting at the end of the childs day:) Bookshelves are great. The library with the ladder is like the old fashioned library. The wallpaper is very 70's, I would prefer something a little less busy.
I think a bunk area is a great use of available, hidden space. There's always a need for extra sleeping space for overnight guests, why not build it in?