It can taste different in the same city / from different sources.
The water sources will be different (mostly filtered city water) and bottled, caned, fountain drinks at restaurants can all vary slightly due to many factors. In some countries different types of sugar/sweeteners may be used, the US has highly subsidies corn so in the us HIGH FRUCTOSE CORN SYRUP is used, where you will see sugar listed in other countries.
Some restaurants will get the mix in bags, others in metal canisters this can impact taste on top of the equipment that mixes and carbonizes the mix.
It can taste different in the same city / from different sources.
The water sources will be different (mostly filtered city water) and bottled, caned, fountain drinks at restaurants can all vary slightly due to many factors. In some countries different types of sugar/sweeteners may be used, the US has highly subsidies corn so in the us HIGH FRUCTOSE CORN SYRUP is used, where you will see sugar listed in other countries.
Some restaurants will get the mix in bags, others in metal canisters this can impact taste on top of the equipment that mixes and carbonizes the mix.
This is only true for coke. Pepsi has centralized bottling. Coke does local bottling.
Points of bottled, vs canned vs the mix at the fountain all apply. Just not the local part.