Hippeastrum reticulatum var. striatifolium is not considered to be a valid scientific name. It's an unfortunate habit of some horticulturalists that, when they find individual plants within a species that are a little different in appearance (especially if the differences make for a superior garden plant), they make up varietal names and distribute the plants under those names.
It's not the proper way to do things. They should either use a cultivar name or, if the plants truly are a distinct variety, they should go to the trouble of publishing a paper through peer review explaining why that is.
