Bairstow, 23, and Buttler, 22, may well find themselves jockeying for the wicketkeeper-batsman's position for many years to come. At present, though, it is the slightly younger protagonist from Somerset who has the gloves.
"There's no easy way into the side at all," Bairstow said. "Everyone is jostling for positions left, right and centre - whether that be batting, bowling, spin department or wicketkeeping. We know the strength and depth we've got within the squad is a very good place to be."
Buttler usurped Bairstow in his country's penultimate Twenty20 match of 2012 in Pune. Then with the Yorkshireman back at home early for Christmas and during England's return to India for five one-day internationals - because of a family illness - Buttler also moved ahead of his misfiring county team-mate Craig Kieswetter.
New limited-overs coach Ashley Giles handed the job to Buttler too in the warm-up campaign for England's ongoing Twenty20 series in New Zealand - and so it was that he kept wicket in Saturday's opening victory against the hosts in Auckland.
Buttler will do so again in Hamilton on Tuesday, when a second victory will wrap up the three-match series early for Stuart Broad's team.
Bairstow currently commands a place anyway as a batsman in the Twenty20 team in the absence of the still rested Kevin Pietersen, but when Pietersen, Jonathan Trott and Ian Bell all arrive this week for the start of a three-match ODI series, he may well find himself on the outside looking in.
Bairstow is one of only five players included in all three squads here - for Tests as well as the shorter formats - but in each, he appears to be second-choice wicketkeeper.
Leapfrogging Buttler behind the stumps still appears a more feasible way back into the ODI reckoning than ousting a clutch of established middle-order batsmen - not to mention his emerging county team-mate Joe Root.
Giles' decision to opt for Buttler last week was a surprise to some with his rival available again, but Bairstow said: "There's naturally going to be competition for places. Jos has got the gloves at the moment and I'll keep working hard - like I have been every training session. I'm working hard on my keeping every day."