Hi Acerswilde, There are a few ways to address this design issue, but I don't know enough about the style and stone and tiles you are considering. Instead of a framed panel, you could consider an accent band of 10" to 12" from ceiling to floor.
Good luck on your project, it's wonderful to renew your home!
Fariba --Archarium

Hi again! Acerswilde, is this the plumbling wall or adjacent? Does this wall hold the shampoo niche? Is this a two-walled shower or three-walled? I take all these aspects into consideration. Best to you! Fariba

Thank you - I was leaning toward an accent band but the salesperson seemed keen on framed tiles. Interesting.

3 walled steam shower with main head on short side, rain shower centered on ceiling and a bench on the other short side. Niche will be roughly the same distance from the short wall as the hand held. I thought a "stripe" would add to the height of the room overall. You enter the bathroom and the shower wall (long side) is the first thing you see.

Thank you for all of your thoughtful comments.

I think the vertical accent band to be more contemporary, artful and fun; I consider the framed panel typically more traditional. On some designs the panel is better, and on others the vertical band is better... this is an aesthetic judgement. You're right about the vertical band giving the room a sense of height.. has an expansive quality about it.

If used on the short wall, plumbing wall, I'd center it and have all the fixtures on this accent field; if used on the longer wall I'd set it off-center, perhaps even two bands of varying widths. Have fun with this!