-First make your bottle between 90 to 100% transparent.
-Apply a reflectivity map to 100%
-Dupplicate your bottle making sure in the prefs menu that all duplication offset atributes are set to zero.
-Unlink your object style.
-Scale the duplicated bottle by one point to tell it apart from the original.
-Apply now your label shape filled with white on a black BG or alpha as a transparency map to your duplicate
-Apply your original label as a texture map.
I hope this may help. Ah! and play with the Hilight brightness & sharpness to taste.