Figured I'd give an update just in case anyone comes across this in the future.
It's been almost 20 weeks in the bottle and still no carbonation so I've decided to do an experiment to try and get them carbed up.
I sanitized everything, popped the tops and added measured amounts of corn sugar to each. 1.8, 2, and 2.2 grams. I don't know if the yeast is still viable but I guess I'll find out in a few weeks.