According to the UK Telegraph, Max Beauvoir, a Voodoo leader in Haiti claims that the evangelical Christians in Haiti have taken over the aid effort and are excluding Voodoo peoples.
But there ARE Voudou organizations on the ground. If you want to make sure that your donation goes to the Voodoo people in Haiti, consider sending it to Voudou Aid, the charity arm of the Roots Without End Society . They are on the ground, in Haiti and dealing directly with the Haitian people and do not discriminate based on religious belief.
Get updates on how they are dealing with the Earthquake here.