Hi Sochi, that sounds like a fun project, it’s good that you’re planning stages. My concern would be having the bathtub on the terrace . A 100 gallon tub weighs about 500 pounds with water. Just something to consider.
I do think it would be very cool, and you’re 9 foot vanity sounds good. Although you might consider two 4 foot cabinets which you can buy standard.
Also, if it’s high humidity, you might want to put a fan over the door of the shower
In the toilet, I think you’ll want to go elongated. So do you walk through the shower to get to the sliding door?
Please let me know :-). Darren

And definitely a bathtub surrounded by plants facing the jungle is amazing. Not to gimmicky at all

Thanks for the input Darren, great points. The support for the weight of the tub will definitely need to be carefully engineered, fully agree.

We will typicàlly access the terrace from the hall outside the bathroom, but if the tub ends up on the terrace we would have access to it from the shower as well.

Two vanities sounds like a good idea, will think about that a bit. Not having a mirror over the vanity (it will be a window) is odd, but I think I can compensate with mirror elsewhere.

Problem solved :-)