Hello. As a member of the Santo Daime church, I thought I could offer some basic information and background.
The most important difference between the Santo Daime and the Uniao Do Vegetal is that the UDV is a single organization, centralized and hierarchical, whereas the Santo Daime is more a movement than an organization, with countless small lines and autonomous groups.
Santo Daime incorporates elements of traditional Ayahuasca shamanism, folk Catholicism (which means a very strong emphasis on the Virgin Mary), Spiritism, and Afro-Brazilian Orixa religions – it is very much the product of the folk religions of the rural people of the jungle. Uniao do Vegetal is more like a mystery school, along the lines of the Rosicrucians, Masons, Hermetics, etc – with successive degrees of initiation into higher and higher levels of the mystery.
The Santo Daime and the Uniao do Vegetal originated in a similar way, but independently. Both were started by rubber tappers who were sent out to the western Amazon during the Rubber Boom, who were introduced to Ayahuasca by the Indians, and received visions instructing them to start a religion based on the sacrament.
Santo Daime was founded in 1931 by Raimundo Irineu Serra, known as Mestre Irineu, the illiterate grandson of slaves. After practicing the traditional indigenous dieta (something like a vision quest practiced by indigenous Amazonian people to contact plant spirits) for nine days, Mestre Irineu had a vision of the Queen of the Forest (Amazonian Indians also consider Ayahuasca to be a feminine being who is the "mother of all plants") whom he identified with the Virgin Mary, and who commanded him to start this new religion.
The original church was in a very isolated and remote area of the far western Amazon, near the Peru border. its original members all either rubber tappers or offspring of rubber tappers and local Indians. Most never went to school and had no contact with urban civilization. They learned the hymns by memory and transmitted them orally, because very few of them could read or write even their names. As a result, Santo Daime has a certain innocent quality at its core that I love. For me, it makes it easier to pray with a childlike open heart.
In the 1970s, the counterculture came to Brazil. Young Brazilian hippies started backpacking around and some of them found the Daime. One of Irineu Serra's main disciples, a canoe-maker named Padrinho Sebastiao, enthusiastically welcomed the hippies. Sebastiao also embraced the marijuana they brought, calling it Santa Maria, the second sacrament. This was very controversial and eventually the church split over this issue.
In the late 1970s, Sebastiao led his followers, a mix of jungle-born peasants and urban hippies, to found an eco-spiritual community deep in the jungle. It is called Ceu do Mapia and still exists today. Sebastiao’s followers also spread his line of Daime (called CEFLU, the Eclectic Center of the Universal Flowing Light) to the cities of Brazil, and from there it has spread to Europe, North America, Australia and Japan.
Given that this line of Daime has "Eclectic" in its very name (and given that Brazilian culture itself is very eclectic and open to mix-and-match spirituality) it should not be surprising that Daime congregations abroad tend to be open to New Age influences, or Eastern or any other traditions that members may practice.
However, despite its openness, Daime is not very attractive to many New Agers because its ceremonies are very ritualized and strict, and very demanding, both mentally and physically. Daime ceremonies, or works (as they are called for good reason) can last as long as fourteen hours. And the Ayahuasca medicine is not a pleasant one. That is why Ayahuasca never has and never will lend itself to recreational usage -- it is not fun, it is an ordeal, and it demands courage.
Daimistas are strictly forbidden to proselytize, to invite, or even to suggest someone go to a work. However, where the church is legal, there are no restrictions on cameras or recording equipment. So videos of Daime works can be found online. Here is a video showing a group about four hours into a work that will go for ten hours, of continuous singing and continuous dancing of the same repetitive steps:
http://www.youtube.com/watch?v=ewc22A4MQ0cHere is a good video from Brazilian television about Santo Daime, including a TV crew visiting the community of Mapia:
http://www.youtube.com/watch?v=4zFRAUJWo8c