Spanish Plan and Spanish Plus are new offerings on YouTube TV. Spanish Plus is a $14.99 add-on for users already subscribed to the YouTube TV Base Plan, which provides access to an all-Spanish lineup of channels.
You can view all of the channels that Spanish Plan subscribers have access to on this page. The Spanish Plus add-on is advertised as having a slightly more limited selection of over 25 networks, but that's just because YouTube TV already bundles Univision, UniM, and Galavisin in its Base Plan.
The three channels that were added to the Base Plan last year are now Spanish-language. It added a $5.99 add-on for Pantaya, a streaming service that caters to Spanish-speaking audiences.
Between now and November 10th, subscribers can sign up for the Spanish Plan for $24.99 for the first six months, or $9.99 per month for the first six months of Spanish Plus. Spanish-language add-ons are available on other streaming services, such as Hulu and Sling TV, but they don't seem to have as many Spanish-language channels. The Spanish-language streaming service from Univision has a free and paid plan with over 100 linear channels.