There have been instances of .es used as vanity domains being requested for deletion: https://www.namepros.com/threads/recepi-es.943453/ so I would be cautious.
Edit: here's the full legal regulation regarding the use of the domain, but sadly it's only in Spanish: https://www.boe.es/boe/dias/2005/05/31/pdfs/A18170-18175.pdf