Thanks !
It seems the situation is fluid.
With Ryanair I need a passport as the driving licence option is being withdrawn.
Aer Lingus allows me to use my driving licence but only for citizens of the UK and Ireland.
As other half is US visa holder, it's a no go it seems.
Aer Lingus - Passport & Visa Information
Ryanair - FAQS : What travel documentation do I need to travel on Ryanair flights?
Thanks for the PMs and replies.