The Chanel bar soaps are nice and long lasting. Guerlain's shower gel (I have the Shalimar) is gorgeous and smells amazing, and the gel itself is blue, sparkly and beautiful. I bought a Santa Maria Novella bubble bath but was disappointed in quality, but I think I accidentally got a really old bottle, so I'd repurchase and try again - the old world style and packaging alone looks so nice on the shelf. For all of the bubble baths I've tried, I think the Honest brand has the best and most long lasting bubbles, but I'd be interested to hear if others have found something better.
(And, not luxury, but a weird thing I've just recently discovered, reminiscent of the 80s if scents really bring you back - the Olay ultra moisture / shay butter bar soap smells exactly like a soap I recall from my grandmother - a yellow bar soap called Tone that smelled amazing.)
Otherwise, put a plant next to the tub, buy a glass/crystal dish for bar soap, and somehow hide/lessen the plastic shampoos, etc. that seem to multiply like bunnies...