Recently happened to me on BHX-DUB-ORD. The gate agents allowed me to board in whatever Aer Lingus sells as premium in BHX but I’m not clear if they were supposed to or just didn’t care (not that it mattered- bus gate) and my baggage allowance was printed on my boarding pass. I forgot what it was but I had a checked bag and carry on and paid nothing. The seat next to me was not blocked, but it really is a short hop.