I guess it depends on how you define "working lines". To me it's is a pretty specific thing. It's doesn't refer to just one person's line or breeding program but to a background and pedigree of dogs selectively bred for the purpose of work. It's a segment of the breed's population being bred for the purpose of work. Plenty of people with show line BCs herd with them but that doesn't make them working line BCs, even if they have relatives who herd as well.
I did use to hear Collie people refer to Farm type Collies, which were AKC Collies that were much like the Corgi "thowbacks" (leggier, short backed Corgis from show lines). The person who initially peeked my interest in the breed had show bred Collies but her first Collie was a Farm type Collie from a pet breeder. I never knew the dog but from the pictures, I'd say he would be similar type to this dog.