Also - This is the layout of the bathroom for reference

your materials are fine. be careful w/your white glass tiles. a lot of people complain because the have a slight blue or green tint to them once installed. You may want to do a sample board with a few of them (get 6-8 and use the thinset to mount them on a piece of wood or spare cement board. bring it into your shower area. this way you can see what they'll look like). Or you could pick a a larger (4x12) white subway tile.

As for you marble/glass arabesque inset, these can be a little tricky to cut and install correctly. do you have a competent tile setter you are using? where is the niche going to be? for something like that tile, I'd make it a lot larger/longer, otherwise, the design will be wasted.

or instead of using it only in the niche, do something like this with it

Beth - Yes I was thinking of doing something along those lines of having a bigger accent tile with the niche inside - that picture is an absolute perfect example! What do you think of making the whole accent tile area inset with 2/3 shelves throughout?

The subway tile I believe is about 3 x 9, we have used it in our kitchen as backsplash and it has a very very slight blue hue to it but its hardly noticeable so I thought that might be a better option

I love your choices, including the vanity. Could you share the sources?