Hello Tomasz.
Have a look if you find "In accordance with JAR_FCL..." anywhere on the license, then it is a JAR license.
If not, it allows you to fly anywhere in the world, provided the aircraft is UK registered.
If it is a JAR license, it allows you to fly anywhere in the world provided the aircraft is registered in any JAR country.
JAA is not an EU thing, so there are some countries outside the EU, even outside Europe who have JAR licenses.
Wether you can work in other EU countries also depends on your work permit, seeing that you reside in Canada.
hope that helps, IP