Yeah no bonus whatever from playing it really.

And yes, once you get all you can at the forest, you can find the chocobo lagoon, you'll need to use your chocobo to get to it. You'll get some chocographs there and bleed that one dry too. After you solve some more you'll get another choco color and be able to do even more stuff! Then you can go back to forest and do some more digging in spots you couldn't before. Again, find the chocograph locations, get a new color, then you can go back to lagoon and go into the deep water! Solve those and you can get the final color! I don't remember if it goes Forest, Lagoon, Forest, Lagoon or a different order. But you have to unlock more colors to get to more places in each. That allows you to get to the Chocobo Air Garden, it moves around the map so you gotta find it in one of... I want to say five places? There is a secret super tough boss there.

The boss is also effected by another minigame thing. Have you ran into any "friendly monsters"? If you find all of them it makes the super boss a little easier.