Is a Polish PhD degree in engineering equally revered as a North American degree (i.e., from Canada or USA) in the area of academia and job-market?
No, it generally wouldn't be as revered. If you look at the university ranking systems, Polish institutions are generally not as well ranked, or regarded as North American institutions. This is also true if you look at the specific rating given for the quality of engineering education within these universities. For example, see:
It is equivalent, in the sense that a PhD from Yale and MIT are "equivalent" (but, depending on department, not equivalently revered).