How do I update my MacBook Pro to the latest version of BootCamp?
Open BootCamp Assistant and open the about window. You should be similar to Version 5.1.4 (500) if you are on 10.10.5

BootCamp gets updated when you update OS X so it's really not dependent upon any version of Windows whatsoever so you would be up date on BootCamp even if you deleted your windows partition and started over.