I do not believe it will give you the equation of any asymptotes. You have to figure them yourself. You can look at the graph and tell where they are, but it will not give you the equation. If I am wrong, I hope someone would point out that feature to me as well. But, your horizontal asymptotes are at x=4 and x=-4.
No vertical or oblique.
You know, that is a good recommendation to send to TI's R&D dept.
That would be a nice feature to add.