I don't know for sure, but you'll certainly find some info in Moodle en Català or in Moodle en Español.
In reply to Nicolas Martignoni
Re: Traduccion al castellano del pluggin tutorialbooking
yes, but they are generic forums of moodle, not of masters (translations)
Carlos,
You can write about the Moodle translations into Spanish, both international Spanish and Mexican Spanish, in the forum for Traducción Moodle al español.
You can also send Moodle messages to the maintainers for the International Spanish language pack.