The nation’s biggest wholesale baking company says it’s going to centralize more of its operations in Kansas City as part of a company-wide reorganization. The move by Interstate Bakeries Corporation could double its employees in Kansas City. IBC now has about 200 people at its headquarters. Interstate’s best-known brands are Hostess snacks and Wonder Bread. the company has 57 plants in the United States. It plans to close some of them but has not said how many.