I can't imagine LL taking the time to implement a per-country filter for anything. Besides, there are LOTS and LOTS of Brazilians in SL. Why would LL exclude Brazil from anything?
But in this circumstance, I think (as others have mentioned) that clicks from continents other than NA may have more latency in reaching the servers, making it even MOAR difficult to win a Bellisseria home. That said, my latency to San Francisco is very low, and I still haven't gotten a house, despite using auto-refresh! There are limitations on how long I can spend on the computer during the daytime, and the competition for them is mind-blowing.
Btw, Brazilians, you have a lovely country. I've only been twice, but both times encountered many terrific people too.