First off, let's clarify the difference and intents of these two very different programs.
WinClone is a product designed to backup your existing Boot Camp partition. While it can be used to port the data from a Boot Camp partition over to a new drive or new partition, that's not its primary intent.
If you want to take this route, you'll backup your Boot Camp partition to an external drive. Then, remove your Boot Camp partition (using the Boot Camp Assistant). Create a new Boot Camp partition (again, using Boot Camp Assistant) to the new size you want it to be. Then use WinClone to restore the image to that new partition.
CampTune is designed to non-destructively resize an existing Boot Camp partition.
In order to use it, you must first use Disk Utility in Mac OS X to resize your Macintosh HD partition to allow adequate free space to resize the Boot Camp partition. Once that's done, burn CampTune to a disc, using the included directions. Boot your Mac from the disc by holding 'C' down immediately after turning the machine on and then follow the instructions to resize the partition.
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In either case, it is imperative that you do a FULL system backup any time you make a major change to the filesystem on your machine. There is always a very real possibility of something going wrong, resulting in catastrophic data loss.