Your 48 SIM will work there if you are on a Guido membership.
But you'll probably be better off shopping around over there for a local SIM.
But that will mean getting a new Spanish mobile number.
If you need to keep your Irish mobile number active then you'll need to keep buying Guido memberships on 48 to keep it going.
Even if you don't buy 48 membership for 10 months you should still be able to reactivate your account your Irish mobile number when you return to Ireland.
Hope this helps.