Why can't I establish a connection in a public/hotel Wi-Fi?
Very often, public or hotel Wi-Fi networks only allow transfer via standard channels like HTTP (webbrowser) or e-mail and block other communication ports for security reasons. Since PhotoSync companion uses port 9000 (on Mac) and port 35722 (on Windows), and the Apple Bonjour protocol uses port 5353 the communication might not work.
However it might be possible to use PhotoSync's integrated web server to access photos/videos from your Laptop on your iPhone/iPad/iPod Touch. Enable web sharing on your iPhone/iPad/iPod Touch, start a web browser on your Laptop and enter the PhotoSync internet address into the web browser. The address is at the bottom of the PhotoSync app window.