You can use a command line tool to relabel the boot camp volume. To do this, cd to the tools folder in the Winclone app:

cd /Applications/Winclone\ 6.app/Contents/Resources

and run this command from the resources folder after unmounting the boot camp partition: (assuming boot camp is disk0s4 and you want to rename it to BOOTCAMP):

sudo ./tools/sbin/ntfslabel -f /dev/disk0s4 BOOTCAMP