Wait a minute--let's back up. A lining is assembled separately from the garment sections and sewn in so that the seams of the garment and lining are hidden.
I've never seen Pellon and other non wovens used as a lining. Is the material sewn into the seams? If so, it is an underlining, which is frequently called a backing or mounting, and used under all major sections of the garment. When used at front openings, neck edges, and on collars or pockets, it is usually called an interfacing or interlining.
Is this important? Yes, many of your customers may have been home-sewers so you want to describe your merchandise as precisely as possible so they and your other customers will know exactly what you are selling. You can always add a note that the lining covers the construction elements of the garment; or, if it is an underlining that it is sewn into the seams to provide shaping for the design.
Claire