In his first two seasons with the Vikings (1985 and 1986), Bono appeared in two games. He spent both seasons third on the depth chart behind starterTommy Kramer and his backup Wade Wilson. At the end of the 1986 season, the Vikings placed Bono on waivers.
Pittsburgh Steelers
Bono then signed as a free agent with the Pittsburgh Steelers. Bono appeared in five games over two seasons with the Steelers (1987-1988). He made his first NFL start on October 4, 1987, against the Atlanta Falcons. After the 1988 season, the Steelers allowed Bono to become a free agent.
San Francisco 49ers
On June 13, 1989, Bono signed a contract with the San Francisco 49ers where he remained for five seasons, his longest stay with one team in his career. The 49ers would win Super Bowl XXIV in his first season with the team, marking the only Super Bowl win of his career. However, he did not play in the game. Bono spent the 1989 and 1990 seasons as the 49ers' third-string quarterback behind Joe Montana and Steve Young. In 1991, with Montana lost for the season, and Steve Young injured mid-season, Bono started six games. He went 5–1 as a starter and finished the season fourth in passer rating. Bono returned to his backup role behind Young in 1992 and 1993.
Kansas City Chiefs
Prior to the 1994 season, the 49ers traded Bono to the Kansas City Chiefs, where once again he served as a backup to his former 49ers teammate Joe Montana. After Montana retired, Bono became the starting quarterback in 1995. On October 1, 1995, in a game against the Arizona Cardinals, Bono ran 76 yards for a touchdown, the longest scoring run by a quarterback in NFL history up to that time.[2][3] In the same season, he guided the Chiefs to a 13–3 record and a division title. At season's end, he was selected for the AFCPro Bowl team. Bono remained the Chiefs starter throughout the 1996 season.
Journeyman years
Bono finished his career with several short stints. He signed as a free agent with the Green Bay Packers in 1997. Bono spent 1998 with the St. Louis Rams. The following year, he signed with the Carolina Panthers.