Plant spots or what?
Hi- the galls on the leaf underside were made by grape phylloxera, small aphid-like insects that feed on roots and leaves. It is considered a minor problem and no sprays are necessary. Remove and crush/discard badly infested leaves to reduce the population. See our page on grape pest problems, including phylloxera, https://extension.umd.edu/hgic/topics/grape-insects.