The Nyclad was (well, is, now) a dead soft lead bullet with a baked on blue Nylon coating. The only purpose of the Nylon was to keep the soft lead from fouling the barrel of whatever you shot it in and keeping powder gas from burning lead off of the base of the bullet. The Nylon wasn't thick enough to interfere with expansion like a copper jacket would be, so they expanded at low velocity.
The Teflon coated bullet was the KTW, the initials of the designers IIRC. It had a green Teflon paint coating and was a jacketed flat point. The Teflon was to protect the bore from the soild brass bullet. I believe the brass construction had more to do with the armor piercing than the Teflon. A pic:
http://www.recguns.com/Pictures/Images/ktw1.jpg
Not the same. The only thing the two have in common is that they are bullets coated in something synthetic.
I've seen some, as well as some THV and some Winchester Hiway Master ammo, and I've actually fired some PMC Ultra mag before it was restricted. That was in .38 also.