You can do that easily if the beads are flat on the back. Some call them glass globs, or glass nuggets, or half marbles but they aren't beads. :0). As another poster said it is difficult to get round beads to stay attached. For starters, I would seal the inside and the outside of the pot. This will not make your pot 100% waterproof, The moisture will soak through in time and it will make your tesserae loose. There is some kind of black sealer you can use too. I forget the name of it. but I think it is used for weather seal on roofs or something. Anyway this product makes it completely waterproof.
Glue your glass "globs" onto the pot with whatever you like, I prefer outdoor rated silicone caulk. Let set for 24 hrs and grout as you normally would. CLean globs well, you can take a pointed tool and scrape the grout off until it is to your liking. Hth PAMA