I have been taught that unlike in English, the -b and the -v are pronounced the same way in Spanish. They both sound like the -b in bat.
For example, "violeta, bola, vino, votar, botar" all start with the -b consonant.
But then I heard people pronouncing grapes as "u-vas" instead of "u-bas." Is this an exception to the rule?
vos
and they pronounce the V.