Generally I have never had a problem getting ssh out on public wifi,
Certainly it is possible on the The Cloud and Purple Patch systems which seem quite common in pubs and bars. In fact it is even possible to get ipsec or PPTP working over them.
The main problem with ssh on phones is limited keyboards make the shortcuts you are used to hard/impossible, also if you are doing this then I would throw screen into the mix to save frustration on disconnected sessions halfway through composing mail etc
Even in the cases where you are encountering blocks on the ssh ports I wouldn't mind betting this is not based on any packet inspection and simply running an ssh server on port 443 or something would get around it. Might be an issue if they are pushing you through an intercepting proxy though I guess and of course you would have to preempt the restriction being in place to get your sshd on an allowed port.