Yes, you can use rib tiles that are about 3/8ths of an inch and six to eight inches long. Daltile and many other companies sell them. I think Porcelanosa sells a cap for their faux Cararra, but good luck on a match. Their customer service dept can tell you weather they make it or not, but I think I used it on a job last year. The easiest thing to do is to cap it with oak that has been oil base primed and oil base painted. You can buy it shaped or have a contractor rout it.

Ask your tile installer to look into the Schluter Jolly product which is a finishing and edge-protection profile for the outside corners of tiled surfaces that come in a variety of colors to match grout as well as PVC and metals. http://www.schluter.com/2267.aspx

Personally I am not a fan of edging and try to avoid it. But now, if you take this edging down, wont it cause more problems for you?
Anyway, when I have cases with the base terracotta tile exposed (and that happens a lot with glazed tiles) I use enamel paint and paint the edges. If I were doing your bathroom, I would hire a tromp-l'oeil artist to paint the edges using enamel paint and feather in the veins. It isn't cheap but it finishes it better and you control the matching.
Let us know what you ultimately end up doing. Best of luck

There should have been a bullnose trim tile, what they did looks like an afterthought and you should have been consulted before they arbitrarily made that decision for you.