Our standard poodles pedigree had champions back more that six generations, only the champs were bred, including one who was a world champion. To me, that's champion bloodlines. My border collie, on the other hand, has a pedigree of 80% working champions. Other than his parents and 3 of the grandparents, all were trialed in the UK, the others were Can-Am champions. BC were not shown in conformation in this country at that time, but I working lines is what I was interested in. This is a champion bloodline.
BYB and puppy mills will use dogs to breed who have not been championed and whose parents have not been championed, often grandparents who have not been championed. So, you are getting puppies who come from a champion three or four or five generations back. Technically, I guess they come from champion lines, but it's a stretch. It's up to the buyer to ask to see the pedigree and figure out that neither of the parents were championed, and their parents weren't championed.