The trip home marked three-month-old Benjamin's first trip out of America.
Bundchen's sister Patricia wed Rodrigo Pereira at a vineyard near Porto Alegre on Saturday (27Mar10). The model served as her sibling's maid of honour.
The big day ended on a romantic environmental note - guests were lit by candlelight only as the bride and groom observed Earth Hour, and joined other eco-warriors around the globe who switched off their lights for 60 minutes.
In a post on her blog, Gisele wrote, "Patricia made a brief speech about the importance of everyone doing their part for the environment. The lights were turned off and the place was lit only by candles. At the end, all the guests gave a standing ovation."