I should probably have specified: I don't represent Matasano / NCC Group in any way shape or form.
That said, I don't think you do. Your question is somewhat like asking if you need to study every medical specialty to the bleeding edge of research to become a general practitioner.
No, but any of them you master will definitely be a boon. :)
Certainly not required! To get a job in application security (at Matasano/NCC or anywhere, really) you should be demonstrably okay at web application, and have interests beyond webapps.
That said, I don't think you do. Your question is somewhat like asking if you need to study every medical specialty to the bleeding edge of research to become a general practitioner.
No, but any of them you master will definitely be a boon. :)