Air units should be seperate units and not just land attachments. Organize them as squadrons, which is more appropriate of the time. It doesn't have to be that complicated. Just bomber squadrons and fighter squadrons.
Since V2 is being made from the start for the 1836-1935 timeframe there's really no excuse not to pay some more attention to this era and especially it's technology.
Actually, having airplanes be division attachments rather than independent units is entirely appropriate for the era. Air forces of WW1 were subordinate to the national armies and navies, only the British separated them into an independent arm of the military (the Royal Air Force), and only at the end in 1918.
Almost their entire activity consisted of army or naval aviation, doing things that directly supported the armies or fleets, respectively. Strategic bombing or other independent operations were quite rare and even less influential.
Since the realistic impact of air forces operating on their own would be so small, I'd rather not have an additional moving part added to the game.
If it was up to me, an air attachment would simply increase the spotting range of a division (to two or maybe even three divisions deep into enemy territory), as well as give a small bonus to fire, shock and organization.