I'm guessing you plan other inhabitants in a tank that size...
As for the Bamboo/Betta combination I really don't know. The shrimp would be as large as the betta, and isn't brightly coloured, but it is very delicate, so even a bad day for the betta could lead to the demise of the shrimp.
Also Bamboo shrimps need a very mature tank, they live on the microscopic inhabitants of the tank, tho that can be supplemented I believe. Not actually kept one.
My betta lives with some Amano shrimp in a 5 gallon, no casualties in so far (6 months and counting). As always it will be down to how tolerant your betta is.