I've never used a shave soap that smells of bamboo. I saw a place online that claims to sell a bamboo/hemp shave soap. The site name is "little homestead farm" I've never dealt with them, but you could look up some reviews and email them and see what they sell and what is costs.
Check out a seller on eBay named sbtanning. They sell a glycerin shave soap called Love My Skin. My wife got me some for Christmas. Anyway they are awesome shave soaps (great lather, cushion & slickness) with fantastic scents! The 1.5oz are $1.75 each with $2.69 shipping (regardless of how many you buy). They must have 25 or so scents and each one is described in detail. I'm sure I saw bamboo as an ingredient in one of the scent descriptions. Regardless they are very good inexpensive soaps. Two are shown below (both smell great) and a 3rd I melted into a bowl is called Perfect Man. It is an amazing scented soap!
A seller on eBay named sbtanning sells one called Bamboo Hemp. The name of the soap is Love My Skin and the description reads as follows; Bamboo Hemp: An incredibly well-balanced blend of bamboo stalks, vetiver, and patchouli, with undertones of hemp seed and oakmoss.
Here are the links for any interested parties Little Homestead Farm Bamboo Hemp Shave Soap Apparently they were featured in one of Wet Shave Club's gift boxes. eBay Love My Skin shaving soap Includes a bamboo hemp scent option Other than the scent, the two soaps appear to be quite different. What is "bamboo scent" anyways? Bamboo doesn't have a scent.