Need advice on puncture

[Vaughanabe13]

AFAIK the tires on this 2009 Z34 have never been replaced and I've got about 11K miles now. The tread is pretty worn and I just got the tire maintenance alert a couple weeks ago. Last week I was driving out of the work parking lot and when I got up to about 20 MPH I heard a loud banging/pulsing sound coming from the rear. Got out and found it was a big piece of wire that was sticking out of my right rear tire and when I drove fast enough the centrifugal force was making the end of the wire hit inside the wheel well. It must have happened in my work parking lot near the shipping dock.

I was able to clip the wire at the base with some pliers and drive home. It was risky but I didn't live too far and I was watching for any TPMS alerts. The tire didn't lose any pressure and when I got home I couldn't find the stub of the wire, so it must have gotten pressed into the tire.

The puncture was pretty much right in the middle of the tread. At this point should I just go ahead and replace the tire? Replace all tires at once? I guess I'm not sure what the average mileage is for these Bridgestone potenzas. I have the 09 Touring Sport.