Where are Bonnie and twill from in cahing fire?

Bonnie and Twill are from District 8, the district known for its textiles. This is explicitly stated in the book and movie when their names are called during the reaping.

While we don't get a lot of information about their lives, the fact that they are both from District 8 strongly suggests they likely worked in the textile industry, perhaps as weavers or spinners.