You can't "call a function on a bean", but you can invoke getters/setters and action processors indirectly. It's actually quite simple:
If you had a property named "beanName" in bean1 which was itself a bean with a property or action method named "functionCall", the preceeding code would invoke it. It's all part of the Expression Language (EL).
Customer surveys are for companies who didn't pay proper attention to begin with.
subject: Calling a function in a bean where the bean name is on another bean as a parameter