I am trying to make 2 spheres inflate with different pressure. The problem is both of them only react to one of the vellum constraint property nodes, I am sure this has to do with the bindings but I have no idea where and what to change them to? Any help appreciated.

when creating their pressure constraint, just assign them different group names
then make each constraint property dop act on different group

Op and or anyone else reading this, Varomix just put out a vellum tutorial that shows how to combine strings and cloth with two different constraint nodes set to the different groups similarly.