I rarely use bonding agent. I think that there may be some similarities in the two, and suggest that you try it out and see what you like. If you are making small containers, I feel that bonding agent is really not needed.
A good mix, not too wet, and allowing the hypertufa to cure slowly, keeping it moist for 2-3 weeks will work better to make a strong container, rather than bonding agent. Just my 2 cents
Mike

Regular white PVA glue isn't generally recommended for concrete, I don't think, but there is one that sort of looks like it, a type of polymer that you can dilute with water and mix with the dry cement, AND you can use it for bonding new to old concrete. (I can't remember the name)

Acrylic bonding agents are said to improve strength and (esp) reduce surface scuffing problems.

If you get either of them, be SURE to read the directions as to use and dilution.

Sue