In order to check the bags all the way through to CGK, you'd have to do it in LAX. I'd be highly surprised if NW has the capability to interline baggage to Jetstar/Valuair. It's not usually the case even with budget airlines in the US that you can interline baggage.

Here's a link to Jetstar's baggage policies.

http://www.jetstar.com/flyingwithus/...rport.html#bag