I prefer camel-case for the xhtml filenames myself, but if there's an actual recommended standard, I missed seeing it.
Backing beans are another matter entirely. If you use JSF2 annotations, the default name applied to the bean will be the bean's classname with the first character lowercased. Beginning a bean name with an upper-case letter is inadvisable, because only Classes should do that, not Instances, per standard
Java conventions.
I normally like to suffix my bean classnames with "BackingBean". It's a bit redundant, since they're usually already located under a "backingbean" package level, but it does ensure that you don't end up with things like "com.x.backing.MyBean", "com.x.persistence.model.MyBean", "com.x.utils.jsf.validator.MyBean" and end up all confused when you see the simple name without knowing the exact context.