Is there a correlation between where I finish my PhD and where can I secure a Postdoc position
In short: your chances of securing a position is higher with people that know you (or someone you have worked with). 

Whether that is people that are physically around you, or people that are working on the other side of the globe (whom you met in a professional setting e.g. at a conference). This is in line with what @la femme consmique, mentions in the comments, networking is important. 

That aside, I have noticed a general skepticism in the U.S. towards Europe. I mean if you are applying for postdoc positions in the US from a European university, you might have to deal with a certain skepticism that does not exist amongst European institutions. It's almost as if you need to convince them that the university actually exists and you haven't made it up on your own (yes, I am exaggerating a bit).

[I would like to make this very clear that this is a subjective statement from personal experience, not a fact.]