Elguagiro,
You'll probably get moved to the Spanish-language forum, but...it appears that the Domincan authorities are a bit over-zealous in their interpretation of the ICAO regs.
The requirements are for proficiency in the language of aviation and aeronautical services where operating. English is only required if there isn't a common language, and only for international operations.
A Dominican pilot should be able to act in all capacities of his/her license, within the Republic, or anywhere Spanish is used, without an English proficiency exam. Non-English speaking countries are not required to make everyone learn English.