Where can I get an list of ATC phraseology terms in Spanish?
ICAO has defined in their Annexes that English is only one of the available langauges to ICAO and that ATS should either use the language specified in the country's AIP or use English.


  1.2.9    Language proficiency   
  
  1.2.9.1    Aeroplane, airship, helicopter and powered-lift pilots, air traffic controllers and aeronautical station operators 
  shall demonstrate the ability to speak and understand the language used for radiotelephony communications to the level 
  specified in the language proficiency requirements in Appendix 1. 
  
  Note 2.— The provisions of 1.2.9 refer to Annex 10, Volume II, Chapter 5, whereby the language used for radiotelephony 
  communications may be the language normally used by the station on the ground or English. In practice, therefore, there will 
  be situations whereby flight crew members will only need to speak the language normally used by the station on the ground. 


Personally, additional to my proficiency level in English, I also hold a Level 6 language proficiency German in my pilot's license.

Below is a screenshot of the Aerodrome Description for LEBL/Barcelona, taken from Spain's AIP. You see that ES/EN is listed as available languages.



If you are looking for Spanish Phraseology, you can find it with Argentina's Administracion Nacional de Aviacion Civil.