According to Blabbeando, the new constitution adopted by voters in Bolivia includes two articles directly addressing lgbt issues. The (small amount of) English-language press coverage has focused on issues of land reform and greater representation for indigenous peoples. But FWIW, the constitution also does the equality-but-not-marriage two-step for lgbt people.The text appears to be available only in Spanish, so I'm relying on Blabbeando (an essential source for Latin American news).
In the title 'Fundamental Rights and Guarantees': The State prohibits and punishes all form of discrimination founded on the basis of sex, skin color, gender, age, sexual orientation and gender identity, origin, culture, nationality, citizenship, language, religious beliefs, ideology, political or philosophical affiliation.
I. Marriage between a woman and a man is constituted by legal ties and is based on equal rights and responsibilities between spouses;
II. Free or common-law unions that meet conditions of stability and singularity, and be maintained between a woman and a man without legal impediment, will produce the same rights as a civil union, not only in the personal and patrimonial relationships between co-inhabitants, but also with respect to sons and daughters who are adopted or born from those partnerships.
Blabbeando has more of the back story, complete with a right-wing ad (with English translation) that warns voters that the new constitution will allow same-sex marriage, while showing two (notably non-Latino) men kissing. The ad's tag line: "Elect God. Vote no." Subtle.
UPDATE – The fundamental rights listed above will apply only in civil courts and not in tribal courts. For more details, see Comments.