In a day of evidence highlighting the intimate professional and personal connections between senior Met staff and Rupert Murdoch's tabloid, the inquiry disclosed the meetings from notes the two officers made in their Scotland Yard diaries.
The inquiry asked Yates about an email sent by News of the World news editor James Mellor to Panton on October 30, 2010, asking her to find out more from him about a bomb found in a printer cartridge on a cargo aircraft.
Mellor wrote: "John Yates could be crucial here.
"Have you spoken to him? Really need an excl splash [exclusive front page] line, so time to call in all those bottles of champagne ..."
Inquiry counsel Robert Jay, QC, was particularly interested in meetings between Wallis and Yates, who in July 2009 decided not to reopen Scotland Yard's investigation into phone hacking after reviewing the progress of the investigation carried out three years earlier.
Giving evidence by video link from Bahrain, where is he helping organise its police force, Mr Yates said Mr Wallis was "certainly a good friend" and had not declared the meals and drinks because they were "private engagements" for which he sometimes footed the bill.
He added that he could not have known at the time that Wallis would become a hacking suspect.
- Independent