I am from Venezuela but live in the Washington DC area. I go to Venezuela every year and I have always wondered if there were. I talked to a guy once on a flight back and he told me he rides with a group in Caracas that poaches the some trails in Avila but you have to be carefull because it is illegal to ride bikes in the national parks. He seemed like more of an XC guy.
On the coast in Cuyagua I did see a guy on a big Kona Stinky but I didn't get a chance to speak with him. I know there has to be some sort of DH riding, we certainly have the terrain for it, it's just a matter of hooking up with someone who knows. Sorry this was probably not much help. If you do find something please let me know.