Under the deal, electricians working for M&E contractor Balfour Kilpatrick will earn the equivalent of a 60-hour week for working a 50-hour, five-day week.
The deal will push electricians' earnings up by £80 a week.
Electricians initially rejected the deal and threatened to walk off the project after Balfour Kilpatrick attempted to impose preconditions.
The firm had demanded increased productivity and wanted electricians to reduce time spent away from site during breaks.
The latest deal was welcolmed by electricians, but they said they were still unhappy about the facilities provided on site.
One said: "Balfour Kilpatrick is pressing the men to use the canteen facilities rather than go to cafés outside the site. But the on-site canteens are a joke.
"People are glad the bonus is sorted out but are getting tired of the way that Schal keeps ignoring the facilities issue. I can see it causing another walk-out if they don't do something soon." A spokesman for construction manager Schal said: "The canteen facilities at the opera house are sufficient for 1000 workers."
Balfour Kilpatrick was unavailable for comment.