The 2015.03.12 update to the website added reward icons to the chain bars. I only added these information till now because they are superfluous to me, since in game I did world bosses consecutively instead of selectively and let the loot pile up. However, this information (including the level of the boss) will probably be useful to newer players and those with limited time and rather do the bosses with the most dragonite yield. So here is the new information added to each world boss/chain bars.
You should see a tiny glob of ectoplasm icon on the chains page, this represent the total number of rares you're rewarded either from the chest on the ground, or the shaky bonus chest.
The yellow box icon represents the number of champ boxes you accumulate, either by killing the champs in that meta event chain (example: two champ ogres plus Foulbear), from ground chests, or at the end as a bonus reward (example: like in Fire Elemental you get two "Deluxe Gear Box").
The dragonite ore icon is the range of dragonite amount you get from looting the final chest on the ground, bonus chests, or opening special champ boxes. This information is taken from the wiki because it's random.
If you believe any of this information is incorrect, please reply to this thread with the proper amount. You can post as an unregistered guest.
Teq chest is 3 guaranteed rares and 20 dragonite ore in the exotic box, 2 champ boxes in the rare box, 1 champ box each in both the masterwork and fine boxes. The ground chest also contains 18 dragonite ore. The ground chest also contains 1g but that's not listed currently.
triple trouble would be a bit of a mess to list because the golden chest contains 5 champ bags, silver and bronze I can't recall off the top of my head but I believe they're 3 and 1 bag. There's also a champ bag that can drop from the individual wurms after they've been decapped. The gold chest contains one guaranteed rare and I'm not sure how many the ground chest is guaranteed to spawn.