Throttle wheelies and clutch wheelies are the same in some respects: No problem if you stick smooth landings. Rough landings in either case are very hard on the forks and steering head, sometimes leading to cracked frames in extreme cases. The K5-6 1000s had a recall since so many stunters were actually causing cracked frames that Suzuki issued a recall to have a frame-brace installed.
If using the clutch to pop the front up, all of the above applies, plus rider skill (or lack thereof) will determine how much abuse the clutch endures.
If these answers aren't self-evident, I'm guessing you're probably beating the crap out of your bike. When I do either wheelie scenario, I've never had any problems at any point in my life..... maybe the occasional 'oops' with a landing that's a little rougher than usual. I've never needed to slip my clutch more than a little to pop-up the front. But I know how to ride.