Is it those printed marble tiles? Pics please. My hunch is that a powder room is not going to have a lot of abrasive traffic, so it is less an issue there than a main floor like a kitchen. We need more info.

Keeping it sealed will help.

My bad, picture posted :) And yes Therese, they are the printed marble tiles.

Rug on high traffic areas.

That IS gorgeous! I agree that a powder room might not get as much use to cause wear as a main bath. Sealing, rug, as others suggested; shoes off would help. But that style tile is still going to be gorgeous even if it shows a little wear over the years. Enjoy it!

Sealing does absolutely nothing to prevent abrasion from wear on a wall tile. The PEI Rating for a wall tile means it is just too soft to stand up to floor traffic. The only cure is a rug, in order to protect it from foot traffic abrasion.