While it is called a soda tax - it is not limited to soda (to anything that has a form of sugar in it) and it is handled as a business licesnse fee RICHMOND BUSINESS LICENSE FEE.pdf that will be calculated on the amount of sugared beverages sold. This makes it easier on the seller in that the many items that include sugar will not have to receive a special sku number or tracked individually. It would be a logistics nightmare for the seller.
From the perspective of the taxpayer - realistically even if you don't buy sugared drinks, the cost will likely be passed on to you rather than the actual purchaser of sugared drinks. If the objective was to curb consumption of sugary drinks - this is not the way to go.