So Mel my first flight from Fiji with Fiji airways on a American Airlines code business class Nan - SFO but a Fiji airplane.... does that mean no access or yes lol... im so confused.
It won't hurt to ask! The oneworld rules for connecting passengers (international long haul to domestic short haul) state it must be a oneworld
marketed and operated flight, connecting to a oneworld
marketed and operated flight. I'm not sure how Fiji Airways, as a oneworld
connect parter fits in to this.
If Fiji Airways is outside the rules (ie it is definately oneworld (AA)
marketed in your case, but possibly not oneworld
operated being oneworld connect
) then unfortunately you probably don't have lounge access by virtue of the oneworld rules. Unless you are (a) on a three class transcontinental flight (you'll need to check if your flight LAX-IAD is a three class transcon) or (b) maybe AA has an exception for their own passengers AA->AA (ie, outside oneworld rules).
My advice - arrive at the lounge, show your inbound boarding pass. Show your onward boarding pass, and ask if you have access.
If not, you can buy access for USD59 as a one-day pass. Or, if you have priority pass, use one of those lounges.
Oh, and please report back
There aren't many data points on oneworld connect as yet.