There are no strict rules for CVs in Argentina. The aim of your Argentina CV should be to persuade the employer to invite you for a job interview.
When applying for a position in Argentina, you may use either Spanish or English, depending on the company and your fluency. Stick to one language once chosen. However, you if your level of Spanish is not high, it will put you at real disadvantage from the local job seekers.
Why not set job alerts in your Global Workplace account and take a look at the keywords employers are using in their job descriptions.