Bonkers so far, but I haven't watched through all of the horror that is the Jonas Brothers yet. So, let's critique "Bonkers" first.
At one point in the song, Dizzee said something to the effect of "And a good bass line is the best kind of silence for me..." I can handle paradoxical lyrics that usually don't make sense as that is what 90% of music seems to have in it, but when you mix paradoxical lyrics with there not even being a good, discernible bass line amongst all of that noise pollution, you've gone officially crazy or "Bonkers." Additionally, there was an incredibly (to the point where I could understand Van Gogh's motive for slicing off his own ear, regardless of the psycho-sexual connotations of that act) annoying alarm or car horn going off throughout the ENTIRE SONG. Also, it didn't even keep time with the beat! It would just randomly play about every 2.666 (repeating of course) beats in the song. The beat wasn't bad, but it was butchered by a blaring alarm. The lyrics must have been written by someone afflicted with the "Kanye West: God of the universe: everything I write is good" complex. Ugh. Horrible.
Jonas Brothers: "Fly with me"
There also really isn't anything to write home about in this one. The song revolves around what sounds like staccato "power chords" played on the piano (1st and 5th note of a chord). The song didn't really move through time very well though. When you have only 2 notes being played in a song, it is very difficult for that song to drive towards a resolution and I think they are relying on a highly trained audience (i.e. an audience who expects after a 4 and a 5 chord a 1 chord thus some semblance of resolution). The rhythm was standard 4/4 with a rock syncopation to it. Again, the lyrics were nothing special what with an insistence on teenage angst being the crux of the entire song: "If I had you here everything would be all right" (or some form of that thought) which wasn't even expressed in a memorable fashion. The lyrics are lame, the music is simplistic, the players seemingly untalented, and at least one of them sporting a molestache. Really? Yes. Again, ugh, Horrible.
After that long rant, unfortunately, I must conclude that Bonkers is the worst of the two songs. Perhaps it is because I'm more comfortable with the rock beat and sounds, but I could, as stated by others above, hear some semblance of that lost art we call music trying to shine from behind the artificiality that is the Jonas Brothers.
Of course, in a battle of "the worst song", saying that one is better than the other is much like giving someone a medal for a bigger pile of shit. Sure, you won an award, but it was still for a piece of shit.