I couldn't find any information on how to become a "cliente personnalité" (which seems to be a French term) of Itaú. However, I can suggest some possible options:

* Contact Itaú's customer service directly to inquire about their client relationship program or loyalty scheme.
* Check Itaú's official website for information on their customer programs and benefits.
* Search online for "Itaú cliente personnalité" or "Itaú loyalty program" to see if there are any resources available.

If you could provide more context or clarify what you mean by "cliente personnalité", I may be able to help further.