Singer Ian Brown said Reni was absent because he had "a really bad cold".
The drummer has had a fractious relationship with his bandmates in the past and walked off during one of their reunion gigs in Amsterdam last year.
Meanwhile, guitarist John Squire said they had written "a few" new songs.
The group, who signed a new record deal at the end of 2011, will be working on a new album this year, he said.
"We won't be playing any of them live until we've recorded it," Squire told the BBC's Colin Paterson on the red carpet.
But the guitarist walked away when asked about what happened in Amsterdam. In the documentary, Reni is shown complaining about sound problems and leaving the stage before the encore.
After the premiere, a spokesman for the band said he had nothing to add about Reni's absence or his illness.
The film, titled Made Of Stone, features footage from the band's career and their comeback shows. It was directed by This Is England and Dead Man's Shoes filmmaker Shane Meadows.
The Stone Roses, whose 1989 eponymous debut is widely regarded in the UK music press as one of the best British albums ever, broke up in 1996.
After a reunion tour in 2012, the quartet have been on the road again this year. They are due to play in Paris on 3 and 4 June before appearing at Finsbury Park in London on 7 and 8 June.
The premiere was simultaneously broadcast to 200 UK cinemas, with a general release on 5 June.
Self-confessed Roses fan Meadows said: "You hear people say 'never work with your idols, it can only go wrong' and I was a bit of a nervous wreck.
"Normally as a director you're in control, you have written a script, whereas on this I was following their lead."
The director, best known for his semi-autobiographic film and television series This Is England, said the documentary was as "much about the fans as the band".
He said: "They [the band] were really open with me, they gave me access to clips, photographs, things no-one has ever seen."
A documentary charting the return of The Stone Roses has premiered in the seminal rock group's home city of Manchester, but drummer Reni failed to join his bandmates at the event.