Do you have a picture of the room so we can see the size and existing layout?

It's going to be part of of an addition/rebuild we are doing. Here are screenshots of the plan for the master and the guest (planning to use the same floor tile for both).

May I ask, why this flooring choice? It seems like a very basic stock choice. (I know, because I have used it! ;>). Yet, you want to do Zellig tile on the walls? I don’t think so. I would start with the Zellig tile and then go from there. But not this tile for this application.

Agree with ptreckel in that your floor choice with a Zellinge tile is a disconnect and in the wrong order. And then add "art deco". Might want to start with your budget. Assume you have a budget for tile? And assume you have a contractor with tile installation built into the contract? Remember your tile choices and design could result in up-charges for installation (and some choices might be beyond the skill of the contractor). So start with the square footage of each area (bath floor, shower floor and shower walls) and the overage requirements. Figure out how much you can spend on tile itself for each area. Then prioritize. Recommend you visit a professional tile supplier and get help from a designer. Not sure what your arrangement is with your contractor but they should be able to direct you.

Zellinge tile is rather primitive in appearance and it seems to me that the flooring selections should be in the same design style. You don't want Art Deco

Seems like the Star & Cross Pattern might be better suited. Run it into the shower area. No need to change tiles.