I was told by my stores director that VL is actually pressed leather, so it is a natural grain, but it is pressed, or rolled, so that is is flatter, and a bit stiffer, but still has the beautliful natural graining patterns of togo or clemence...As if you were to take togo or clemence and flatten it.
Epsom, on the other hand, is embossed, meaning the graining you see is applied to the leather with a kind of stamping process. It is a thinner leather than VL, and the embossed pattern is manmade.
RBB, i think your bag is vache naturelle...very pretty herbag, BTW!!!