Roman shades could provide something unique and personalized look.

I think either one would work. Roman shades give you more color options though depending on the prints/color of the fabric. Color options that you can perhaps use as inspiration for paint colors and bath linens.
I wouldn't not recommend adding a roman shade on top of the blinds though. I think that would look overdone.
My recomendation would to do either the roman shade or bamboo shade but have it configured with a top-down bottom-up feature.

I think the smaller window would look better with just a black inner rim and no shade. The bamboo sounds a better choice for the unfrosted window - while the roman choice is pretty, it is less practical both for privacy and mildew concerns. Perhaps you could inject the color scheme from it through linens, or shower curtain.