I too, was interested in this so I had a little look into it.
If you visit the hyperlink (http://prezi.com/ftv9hvziwqi2/coca-cola-companya/) on an iPad, it gives you the link required to open the presentation in the Prezi app.
This is it:-
prezi://open?oid=ftv9hvziwqi2&details=eyJzaXplIjogMTIzMTE2MywgInRva2VuIjogIiIsICJ0aHVtYl91cmwiOiAiaHR0cDovLzA0MDEuc3RhdGljLnByZXppLmNvbS9wcmV2aWV3LzgvOS83L2M3M2U3NTU5YTE3ZjdkMjgyMjc1NGIwOWVkNmY2ZDJhNjNkZmFfMV92OTkucG5nIiwgImF1dGhvciI6ICJBbm5pZSBOYW0iLCAidGl0bGUiOiAiQ29jYSBDb2xhIENvbXBhbnkuQSIsICJsYXN0bW9kIjogIjA4IEFwcmlsIDIwMTIiLCAib2lkIjogImZ0djlodnppd3FpMiIsICJkZXNjIjogIkludGVybmF0aW9uYWwgbWFuYWdlbWVudCBwbGFuIn0=
It turns out there is a second parameter called 'details', which is base64 encoded. When I decoded it, the details look like this:-
{"size": 1231163, "token": "", "thumb_url": "http://0401.static.prezi.com/preview/8/9/7/c73e7559a17f7d2822754b09ed6f6d2a63dfa_1_v99.png", "author": "Annie Nam", "title": "Coca Cola Company.A", "lastmod": "08 April 2012", "oid": "ftv9hvziwqi2", "desc": "International management plan"}
I'm guessing this 'details' parameter is required, so try creating your own and base64 encoding it. Good luck!
Edit: A much simpler possibility is to direct the user to safari. That way they can still open the Prezi app, and you don't have to create any weird details yourself.
NSURL *url = [ [ NSURL alloc ] initWithString: @"http://prezi.com/ftv9hvziwqi2/coca-cola-companya/" ];
[[UIApplication sharedApplication] openURL:url];