A condy or tube anemone might make it since they are really hardy and dont really require special care, anything fancier than that I dont think it's enough. And another thing...what kind of lighting?
JMO, I'd say the lighting wouldn't be an issue as much as the water volume of only 5.5 gallons. 80 watts for 5.5 gallons equates to 14.54 watts/gallon... more than enough IMO. But keeping water conditions stable enough for an anemone to thrive in a pico system is a very difficult task.
I would second that about the tank size. 5.5g is really small and anemones can be messy eaters. It's going to be very hard to maintain excellent water quality, even with frequent water changes. Even with frequent changes, each one will be magnified in its effect in such a small size. Those types of ever changing water conditions are not, IMO, condusive to a happy anemone.