If a Firebender gets boosted by the comet and Aang is also a Firebender, shouldn't his Firebender abilities also be stronger with the sun?
And of course the same with the moon and his waterbender abilities.
As the wiki suggests Aang also effected.
An Avatar-level firebender can produce fire whips, the most being five at once. They are capable of reaching across long distances, displayed when Aang used the technique hundreds of feet above Ozai. This may have been a result of his firebending being augmented by Sozin's Comet or because he was in the Avatar State at the time, or possibly a combination of both. Each fire whip is also very wide and moves in a similar fashion to squid or octopus tentacles. They have enough destructive power to demolish large rock formations.