It is a sunni practice to recite Fatiha and other surahs for esal e sawab.
Even Imam Shafi has been quoted as saying there is no harm in it. There is some references for Prophet SallAllaahu Alaihi wa alihi wa sallam doing it, the tafsirs certainly mention such practices as Sunnah from weak sources.
Hence overall it is not said to be authenticated Sunnah but as mustahab (recommended and allowed practice)