Mrs. Albert G. Witkopf of 56 Maple St., Tonawanda. has announced the engagement of her daughter, Bonnie Sue, to Joseph Allen Matthews, son of Mr. and Mrs. Raymond Mazuca of 196 Frederick Road, Tonawanda. The future bride is a June graduate of Tonawanda Senior High School Her fiance is a 1967 graduate of THS He attends State University College at Buffalo (Wiech Studio)