As worded, I would say that the increase of E&L are independent of the band, so you may increase them 2/2 regardless of the band. I would also say that it is not an ongoing ability, so the increase is permanent.
Apollos could go either way ("If Paul is in battle, increase Apollos 2/2" would make it instant, whereas "While Paul is in battle, increase Apollos 2/2" would be ongoing and thus would end when Paul leaves battle.). I would lean toward the 2nd interpretation, but am not sure.
Mary could also go either way, but in her case I would lean toward an instant/permanent increase (If it is December, increase this Hero 3/3 vs. While it is December, increase this Hero 3/3.)
So if I had to make a judgment on all of them, I would say all but Apollos are instant. It might make more sense to make them all consistent one way, but I think the variations in wording do make a credible case for one way or the other. And I personally think getting a 15/15 or greater Mary in games during December would be cool. Also, it would help figure out what to do when a battle during a New Years Eve tournament goes past midnight before resolving...