I've been helping companies market to Spanish speakers for over 5 years.
As with most questions that stretch across borders and cultures, the answer is, "it depends". Here are some of the factors at play:
1) US Hispanics are over 80% of Mexican descent, meaning that as a general practice, your marketing can be similar
2) But their situations are very different. In the US (according to census data), Hispanics trend lower income. But for products that have a US price point, you are going to have to appeal to wealthier Mexicans (for example).
3) Depending on your product/service, you may have to adapt pricing/messaging to fit cultural norms, or what people can afford.
4) Other issues: if you are a content company that sells advertising, you may want to EXCLUDE people from LATAM, as many advertisers are only trying to sell in the US.

Obviously to give good advice I would need more context. Feel free to set up a call with me (I donate all proceeds to charity), and I'll be glad to talk through this with you.