How is it going to have an inflationary effect when workers are already making that money? I don't really see how increasing menu prices or adding an automatic 12%-15% on the bill to avoid playing games afterwards with the receipt is a bad thing.
If costs rise, prices have to rise to maintain margins. Textbook definition of Inflation.
If there's 15-20% (discretionary) added to the bill, it's not perceived as the price but rather as a "thank you" for taking care of us during our experience.
Again, I don't like this system; and would welcome a viable alternative!