I think you need a little more time for a few reasons.
First, you got TS staff not so long ago. Yes, it doesn't necessarily mean you aren't ready but more experience wouldn't hurt right?
Second, with all honesty I don't see you do much on teamspeak to a point it excels for you to deserve the promotion. Try being more interactive with more users and helping more cause from what I've seen and noticed it's not there just yet.

Best of luck