i'd let the floor bridge the two instead of matching either one. a warm greige or soft taupe porcelain with a little movement plays nice with honed marble and won't fight the wood vanity. keep it a step darker than the marble so the wainscot reads crisp, and pull the grout from the marble veining. if your shower floor tile is already in, echo that tone so the room feels like one story.

thank you !.

What is the exact "wood tones" of the vanity? I see no reason for marble halfway up a choppy wall in what seems a choppy layout.

From what I see? Repeat on the floor, whatever is on your shower WALLS.....

What is vanity top?

Larger spaces that are toughrt to change first. Start with the floor. And since you are doing this piecemeal instead of a full plan before starting match the wall tile. The room is a sum of the parts and all the parts need to work togther which is why the bigger tougher to change areas (ie floors) need to be chosen first or at least together at the same time as the balance of the finishes.