Yes.

Basically, all epoxy is made by one company:I believe its Dow. The differences are additives by each individual packager. As a result, different brand epoxies bond just fine with each other.

To take advantages of different properties, I've applied West directly over uncured MAS and it works fine. Bonding to cured epoxy is just like bonding to any cured epoxy, you should clean and sand as appropriate.