Greetings always require acknowledgement with a respectful smile.
It is considered polite to greet every member of a group individually. The same applies when leaving. Remember to carry an ample supply of business cards and exchange them immediately during greetings. It is not strictly necessary to translate cards into Spanish because most Mexican businesspeople can read English even if they cannot speak it, but doing so will leave a good impression with your Mexican contacts. Be sure to include your official title and any degrees, because they carry weight in Mexico.