Well it looks like you're close, though I can't say it fits the desc. exactly. The bark and trunk is different, and also the seed pods are smooth and only 1/2 moon, not 5/6 of a circle as the picture you linked to was showing. I would guess its in the same family though, and sounds like you're on the right track. Also is my tree just a single tree with many trunks? Or was that 6 trees planted together that formed into 1 base?

Interestingly, my passion vines (P. edulis) don't have any caterpillars on them. However, my potato vines have so many on them, that most of the leaves are gone. To save the other vines growing nearby, I had to spray with some organic caterpillar/bug killer (got it from Home Depot). I hate caterpillars, and by extension, butterflies too. They almost defoliated my plum trees.

It is normal for citrus to drop older leaves, especially on established trees like this one. And it's always a good idea to fertilize regularly. But on the third leaf from the right, I think I see Whitefly larvae and their white stuff they leave around them. And I think the first two leaves may have a little bit of sooty mold, which would come from the Whitefly larvae droppings, a sweet sticky substance. It looks like a pretty mild case. On a tree that size they won't really damage it, it's more of a nuisance then. But if I were you I'd take the hose with a spray end and give it a good hard wash with water, especially on the under sides of the leaves. That will get rid of a large percent of them, then I'd do that every week for a while, say a month or so. That will help get rid of new ones as eggs left behind, hatch out. Overall though, johnmerr and pip are right, it's in pretty good shape, just need some food.

What constitutes a bonsai (bone-sigh) tree is a very subjective topic, even within the bonsai community. To a beginner, anything in a bonsai pot is a bonsai. As they progress, most begin to realize that a bonsai tree is an evocative and believable representation of a tree we might find growing on a mountainside, meadow, or in any other natural setting, so their view of what constitutes 'bonsai' changes as the practitioner grows in the art. As someone who has judged bonsai shows I can say, if the tree doesn't evoke emotion or lend itself to a story, there is still a lot of work to do on the tree. Part of the work needed to improve an unimpressive tree is most often more refinement, which makes the tree appear older and more realistic - part of being evocative of a story. As bonsai practitioners evolve, some of them readily let go of the need to tell people their tree is really a liner (a liner is a very young tree, usually 1-3 years old and often sold in groups of 100 - 5,000 or more) in a pot. They understand and remember there was a time that a liner in a pot defined most of the trees in their collection, and how proud they were to be a member of the bonsai community and practicing the art of bonsai. Unfortunately, there are a few bonsai practitioners who are always ready to tell someone what is a 'bonsai to them' really isn't. That's unfortunate. I don't think people should ever be discouraged from trying their hand at any horticultural endeavor - especially when it comes to bonsai, which to me is ever-evolving art with a 4th dimension, that of life. The personal rewards and satisfaction it offers are unlimited; and for a lifetime, you can continue to grow in all the aspects that make up the art. The satisfaction of being on the journey is much more important than being the best, because the rewards that come from learning and trying, and the delight of achievements realized along the way accumulate and last forever. So personally, if the OP has a ponytail bonsai, I'm good with that, and I encourage her/him to learn all (s)he can about the plant and the art, because it's that knowledge that will move you forward. Al