This site displays specific percentage badges on two package tiers — "38% Saved" on the 6-bottle package and "13% Saved" on the 3-bottle package — worth understanding the arithmetic behind each.
Against the $79/bottle price on the 2-bottle package, $49/bottle on the 6-bottle package works out to roughly 38% less, and $69/bottle on the 3-bottle package works out to roughly 13% less — worth confirming that calculation yourself.
Worth calculating the percentage yourself from the stated per-bottle prices, rather than relying on the badge alone, since it's not stated which specific reference price the percentage is calculated against.