Some background: retailers in California that sell taxable goods have the choice of either including sales tax in their posted prices (“tax incl”) or not (“+tax”). Whichever they choose, they must disclose which method they use and must be consistent. Retailers of tax-free goods obviously don’t need to make this choice. Vending machines invariably always include the sales tax (and CRV if packaged beverage) to make the price a round number.

non-prepared food items no longer have sales tax

This is mostly correct, since the sales tax on food is generally on hot food that is otherwise unprepared. If any other preparation occurs (like with a sandwich from a sandwich shop), then that added preparation makes the whole sandwich taxable, even though the individual food ingredients would have been tax-exempt.

The only taxes I know I would be paying for a canned soda would be the CRV/California Redemption Tax, which is a flat $0.10 per aluminum can.

Minor quibble: CRV is California Redemption Value and is a refundable fee. The tiny distinction from a tax is that fees are potentially refundable (and this is, upon recycling the container) whereas a tax is virtually never refunded in any scenario. That said, the California Constitution specifies that taxes and fees have the same requirements when it comes to approving them, since the payment of a tax or fee is mandatory. But I digress.

Anyway, the rates that you described is not correct. The current rates are:

5 cents for containers less than 24 ounces 10 cents for containers 24 ounces or larger

And only applies to aluminum, glass, plastic, and bi-metal.

So on a can of NOS (16 fl oz) pays just 5 cents, but a 24 fl oz can will pay 10 cents. I’m not sure which size can you were looking at, but I’m going to guess it was a 16 fl oz can.

If 16 fl oz priced at $1.98, then add 5 cents CRV, that’s $2.03. The California Department of Tax and Fee Administration (CDTFA) writes that:

Sales of noncarbonated drinks are generally not taxable, but their containers may be subject to the CRV. On the other hand, sales of carbonated and alcoholic beverages are generally taxable, and the CRV fee that is charged for their containers is taxable

And:

Under SNAP, we consider items purchased with CalFresh benefits as sales to the United States government, and those items are therefore exempt from tax in California.

And:

Sales of eligible food items purchased with CalFresh benefits are exempt from tax, even if the sale of the food item is normally taxable. For example, the sales of carbonated beverages, ice, and food coloring are exempt from tax when purchased with CalFresh benefit

So if you’re somewhere within, say, San Francisco where the sales tax rate is 8.625%, then that brings the $2.03 up to $2.21 if bought without CalFresh, since both sales tax and CRV apply, and CRV is itself taxable. But on CalFresh, neither sales tax nor CRV apply, which would just be $1.98.

This all appears to align with your observations.