It should work if you have a Guido membership while roaming in the EU.
If you don't have a Guido membership then it will definitely not work at all - i.e. no calls, texts or data.
Even with Guido membership some users have had problems for some reason that 48 support have not explained or addressed.
In some cases service simply does not work even though it should.
In other cases calls/texts work but data does not.
In that case if that happens check the internet settings and if the APN field of the settings has changed from 48months.liffeytelecom.com then edit it, change it back to that, reboot and try again.
By the way - you seem to be using an iPhone in which case you should be aware of this issue due to the stupid way that Apple do things:
Hope this helps.