Hi & welcome! Bonsai means "tree in a pot" so yes, it's a bonsai if you want to call it that. It looks like Pachira aquatica, AKA money tree.
Money Tree (Pachira aquatica)
A more stringent definition is a woody entity that has been manipulated over many years to resemble a full-size, unmolested tree.
To keep it small and looking bonsai-ish, it will need periodic maintenance to the above-ground parts and roots. There are many books & websites dedicated to teaching the ancient art of bonsai. If you're not into all that, you can just treat it like any other potted tree: repot every year or two, chop off parts that get too big.
