Banahan received a three-week ban on Tuesday after he was sent off for a dangerous tackle during last weekend's Premiership clash against Leicester.
Mears was cited for punching in the same game and landed a two-week suspension.
Both appeals were heard by Gareth Rees QC, the Rugby Football Union announced, with centre Banahan remaining sidelined until December 24 and hooker Mears being able to return seven days earlier.
London Irish player Chris Hala'Ufia, meanwhile, appealed his five-week ban imposed after he was red-carded for a tip tackle against London Welsh last Saturday.
A decision on that appeal is expected on Friday.
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