Heather Knight in her October 9th San Francisco Chronicle article, details how even retailers used by the beverage industry in their "No on HH" ads understand its not a grocery tax and plan only to place the tax on sugary drinks.

One store owner shared how ludicrous the idea of rising rices on everything in his store would be. "Nobody's going to want to raise the price of a loaf of bread or a box of cereal to offset the cost of soda" he said. "Then the price of cereal wouldn't be in line with the competition."

The article also highlights two separate studies being conducted in Berkeley that showed grocery prices have not gone up.

http://www.sfchronicle.com/politics/article/Big-Soda-s-tax-claim-falls-flat-with-grocers-9957316.php