Fine except all OneWorld Emerald even if flying Y are able to use First Lounge at T4..Concorde is for F Class only.

Lounge Access by Tier Status
Emerald: When travelling on any of the oneworld member airlines, any customer who has earned Emerald tier status, is welcome (with one guest travelling on a flight operated and marketed by a oneworld airline) at any oneworld airlines' pre-flight lounges, including First Class, Business Class and frequent flyer lounges regardless of the class they are travelling in.