On the APP when I click receipt: "FLIGHT TOTAL $0.00" plus an entry for taxes.is also listed.
I did a couple of searches on the DL Vacations travel agent portal. The air itineraries clearly indicated "Published" (LAS) vs "Unpublished" (HNL) from the start of the booking process.
When I tried to book LAS on the consumer-facing website, there is no indication of fare type. The TA portal, "WorldAgentDirect", is about 10 years behind in terms of "sizzle" but runs much faster. I think it's based on tech developed by NW. Oddly, it handles the flight options first, then hotels, unlike the consumer site.
I wish I could provide more concrete guidance, other than a travel agent can tell you upfront in the process whether the package uses published fares or bulk/"unpublished" fares. Also, it looks like TAs are able to redeem vouchers for client bookings--did not expect that.