Black Sabbath were given the freedom of the city of Birmingham in a ceremony in the city last June just days before their Back to the Beginning farewell gig at Villa Park thrilled music fans from around the world in July.
Frontman Ozzy Osbourne died 17 days later at the age of 76.
Iommi said it had all been “unbelievable” to see the huge number of fans coming to see them and sit on the bench on the renamed Black Sabbath Bridge over the canal on Broad Street.
“I saw Michael Buble on it – it’s brilliant.”
He said he was working on an album which will be launched in Birmingham at a later date and planned to auction off another guitar to help fund refurbishment work at a cancer ward at the Queen Elizabeth Hospital in Birmingham.
The council said its award to Wagner recognised his leadership and contributions to Birmingham’s sporting landscape through football, netball and cricket.
The planned development of Birmingham City’s new stadium and the wider Sports Quarter in the east of the city as well as enhancing the city’s transport infrastructure, further strengthened Birmingham’s national and international profile, the authority said.