Mr. and Mrs. William Winslow Byington Jr., of Rome announce the engagement of Emily Allgood Griffin, daughter of Mrs. Janet Byington and the late George Griffin Jr., to Bryan Thomas Johnson, son of Mr. and Mrs. Denny Dobbs of Covington and Judges Edward H. Johnson and Carolyn Weeks of Social Circle. Miss Griffin is a 2002 graduate of Darlington School. She debuted at the Rome Symphony Orchestra Debutante Ball in 2003.