Air New Zealand Air Points - NZ codeshare on UA in L books into ?? on UA?

I'm looking at an NZ itinerary with an SYD-SFO leg as a codeshare on UA. The NZ booking code is L. What does this book into on UA? Is it W+ so I can use my SWUs?

L is one of the cheapest booking classes so probably isn't upgradeable on UA (besides which doesn't the flight have to be booked with UA flight number in order to use a SWU?).

Ahh, okay. (No, UA flights can be SWU'd at the gate if purchased under a codeshare.)