Recenty, I was booked to fly on TAP airlines from Newark Liberty International Airport (EWR) to Lisbon Portela Airport (LIS). On my way there, I flew on their Executive product (aka business class) and on the way home, I flew in economy.
At the airport, I looked for a priority line, but did not see one, so I waited in the standard line. Upon check-in, I was provided with a green sticker on my boarding pass, which indicated I was to receive an expedited security clearance. There was no discussion of whether I had lounge access and the ticket agents did not seem to know — actually, different agents told me to go to different lounges.
I was a bit frustrated, but it was only an hour until my flight anyway, so I decided to relax in a secluded part of the gate with the economy passengers. Checking out TAP’s website, I was able to confirm that I had access to the Lufthansa’s Business Class lounge in Terminal B.