If you plan to usually leave the door open to the powder room, I would have the woodwork match. If you don't, then do what makes you happy on the cabinets. As far as colors, I like ice blue in the bedroom and ecru in the powder room. That's what I've had for the last 5 years since we had to rebuild (after a fire) and I still love the colors. (Remember not to use yellow or green in the room where you will apply your make-up.)

Hi, your home looks pretty good, you have done a lot on the interiors. Coming back to the question, yes, you can add a wallpaper behind the television, go for a textured wallpaper as it will create a compliment to your television. As you have decorated with wooden elements, you can go with a bookshelf on the wall. And, there is one more thing which will be a simple addition but will look perfect and that is an antique wall clock. An antique wall clock will make your wall look great without any fuss.

Howards Storage have some but like most I think the mirrors are small. I also found a really nice one on Marks & Spencer and they have free delivery in September. (it's not really in the style you were wanting sorry) http://www.marksandspencer.com/square-extendable-mirror/p/p22319481?source=affwindow&extid=af_a_Content_79682&comgp=79682&awc=1402_1411636962_c6aa0b8cc845d5ae78080e37730547c8

Artist called Donna Butler can do something like this for you https://www.facebook.com/donnabutlerart/