While WoWI may not have any policies against using Photobucket, I would personally suggest you use an image host that doesn't depend on tons of non-standard JavaScript that doesn't work in all browsers. For example, I can't view full-size images on Photobucket in Opera without viewing the page's HTML source, reading through the semi-obfuscated JavaScript to find the full image URL, copying it, and pasting it in my browser's address bar. Worst of all, the entire site is totally dependent on JavaScript, and nothing works at all if JavaScript is disabled. It's probably even worse for people with actual disabilities.
imgur.com is a good option, though I'm sure there are others too.