I'm going from HNL to CGK. HNL-NRT-HNL is UA and NRT-CGK-NRT is a codeshare with ANA.

The itinerary shows that from HNL-CGK, I get two free bags at 70 lbs. each. On the return it shows one free bag at 50 lbs. and $100 for the second bag?

I went to the UA website and it says:

We have revised some of our checked baggage policies for travel worldwide. For the latest checked baggage updates, please review all relevant baggage pages before you travel.
Updated: December 18, 2014

So I have to pay $100 for a second bag even though I'm a *A gold?

Here's what's interesting. When I input my flights it shows I have to pay $100. When I input just CGK-HNL it shows three bags free.

Check up to three bags at no charge
Baggage check-in must occur with United or United Express, and you must have valid MileagePlus Premier® Gold membership at time of check-in to qualify for waiver of service charges for up to three checked bags (within specified size and weight limits).
1st bag
$0
2nd bag
$0


Sat., Jan. 10, 2015
Honolulu, HI (HNL) to Jakarta, Djakarta ID (CGK) $0 $100 $0* 70.0 lbs (32 kgs)
Sun., Jan. 18, 2015
Jakarta, Djakarta ID (CGK) to Honolulu, HI (HNL) $0 $100 50.0 lbs (23 kgs)