Sometimes it's not about finding a job but about getting a visa. Some employers mght require a certain level but those are probabaly professional jobs. If you're looking for a job in a cafe then they'll judge your English in an interview.
I am pretty surprised about these visa requirements from Australia and Canada.
Thankfully I don't need to search for a work abroad for now, even If I had to, I would choose some EU member state of state like Norway, Switzerland where there is open job market for EU citizens.
But I must say, that Germans, for example are pretty iritating with their scrupulosity with documents, for example diplomas. I had to translate all my certificates and it cost me about 70 euros. Although I have no experience in other EU countries, but I know that in UK for example (or Ireland)there is bigger liberalism with documentation. France or Belgium which are known for their bureacracy (similar or even bigger to German or Austrian, but probably not bigger than this of Poland)probably also need "everything on the paper".
Danielle rather thinkgs about EU regulations and domestic regulations in particular member states. There is no need to have any certificates in positions not related to public services or to those position which are related to use of the fluent language. I do not have any kind of certificate (although I though about CAE, then CPE certificate or Zertifikat für den Beruf). In fact, they are useless, I was working in Germany and Austria and noone wanted any kind of certificate (I had been pretty fluent then with my German, I had had direct contact with German native speakers before I left).
But on some position, especially related to public service, for example in Poland, such certificates (for English mostly)are of the most documents, needed, just like other diploma.
I agree with Amanda - your qualifications (including your language certificates) are more an issue for the country that will give you a visa, instead of what your employer wants. As far as working abroad goes, check with the country's visa regulations. I understand that Canada and Australia both require an IELTS certificate.