As you may or may not know, the Golden State was originally made of several mini-lands including Condor Flats, Bountiful Valley farm, the Bay area, and Grizzly Peak Recreation area. When they added Flick's Fun Fair, they turned the Bountiful Valley farm area into "A Bug's Land" which included Flick's Fun Fair, ITTBAB and a smaller Bountiful Valley Farm area.
I'm not exactly sure if the distinction is crystal clear. Since that area was part of the Golden State district when the park opened, I would say it is a miniland within the Golden State. However, the new guide maps list the attractions for the Golden State under one heading and then all the attractions in "A Bug's Land" under a seperate heading as if it was its own land. Honestly, I think its up to you. I personally see it as a miniland. I think it fits into the park's California theme better if its considered part of a bigger land then just its own separate land where arguably it has little to do with California.