Bonner played in seven of Ireland's eight games in the qualifying round of UEFA Euro 1988. Despite some good results, including a 1–0 win away to Scotland, a 2–0 win at home to Bulgaria and a 2–2 draw away to World Cup bronze medalists Belgium, Ireland looked to be losing out on goal difference to Bulgaria. Bulgaria needed only a draw against Scotland in their last match to progress. However, a last-minute winning goal for Scotland gave Ireland, and Bonner, a first appearance at the UEFA European Championship.