I like 12 x24 floor tile and I use the same for the tub surround or shower walls I dislike wood look tile and also think it is a dated look IMO the fewe the finishes in a bathroom the longer it willbe less dated. I need to see your space and I have to say the pic with the tub honestly is a claening nightmare with those tiles. The onyx look tile is loveley but IMO too busy to be used for flooring or wall tile in a shower . I would suggest you buy a box of those and lay them out to see what they will look like in a big area. I think if you like them use a simple on colr no pattern porcelain tile 12 x24 for floors and shower walls and use that pretty tile for a vertical strip in the shower and then use it for the back spash behind the sink. You will need to find a porcelain tile in a color from the onyx . I have no idea how the gray tile is working with anything else you show .

I love the look of shiny but went with matte in the shower for it shows far less water spots. I am happy I did.

Thanks for the insight- Yes I too dislike wood "look" anything but found myself drawn to the natural color "ribbon" wood tile. It is very textural and that does worry me. I wouldn't use the gray, it would be in the natural color- perhaps I can find a similiar tile without all the texture and not necessarily "wood" look but also thin vertical lines. This mock up from the tile website shows the mix of the ribbon and the onyx, ignore the hidious floor tho, my floors will be a very neutral LVT. I have a small sample of the ribbon I will start showing with it to test it out!

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You are not doing a palatial bathroom like the one above my post. You are doing a bathtub that is also a shower, right? You will have to squeeze just a bit of the ribbon tile on either side of your onyx-look center square, and it will not have the same effect as a 9 ft wide swath of it on the wall next to a freestanding tub with a square of onyx tiles, a ceiling that reaches for the heavens and the light of 8 foot high windows on all sides. It will be a small, dark, dingy cave that you are going to spend hours in, getting soap scum and maybe hard water stains off of textured tiles. And about those 24” wide tiles - your tub shower combo is 30 to 32 inches wide. How do you avoid the “sliver of tile at the end “ effect with 24” tiles? Look at bathrooms that are the size of yours and see how choppy it is to use all those different tiles in one room. I would also suggest you choose either cool grays or warm caramel’s. They do not mix well.
Go to the “photos” section of Houzz and do a search on “tub/shower combo” and see what looks you like. Keep in mind that the current trend is toward fewer tile choices and a more cohesive look, no lines of deco tiles cutting walls into sections.
If you don’t like to clean, look at Corian, Swanstone, and other solid surface products. Ones that are true solid surface have the same color all the way through, no gloss layer, and can be sanded with a 3M kitchen scrubbie if the were to somehow get scratched or scuffed. I have had my Transolid shower 2.5 years now and never scrubbed it once, just wipe down the walls or squeegee after most showers and clean the floor.