I want to know if it can be grown as a Banzai.

The spelling is bonsai. With very few exceptions, only dicots (Magnoliopsida)
among the flowering plants can be used for bonsai. I have a pygmy date palm
which is called a bonsai by courtesy, because a true date palm is 100 feet tall
and a full size Phoenix roebelenii in a mall is 50 feet tall. It grows one to
three trunks & is in a 10 inch pot. Every other year or so I repot it & hack
off most of the roots. At least a palm has a somewhat woody trunk. A banana is
an herbaceous plant. Some species are smaller than others, but not bonsai
material. Can't you find something else?

Iris,
Central NY, Zone 5a, Sunset Zone 40
"The trouble with people is not that they don't know but that they know so much
that ain't so."
Josh Billings (Henry Wheeler Shaw), 1818-1885