T-Verb was released after Anthology X was released, and also, Anthology X was intended to be a release of the Anthology II plugins as native plugins. We will release a new version of the Anthology bundle in the future to include whatever plug-ins have been released since Anthology X came out, but like other plugin companies are doing, we plan on doing that on a more or less annual basis.
Or you can do a subscription deal with the new Ensemble bundle, where everything is included (Black Hole & 2016 are also not in Anthology either).
Whatever way you do this – buy it as a separate plugin or in a bundle – I really cannot say enough good things about this. I bought it on day of release (I checked to see if it was in Anthology Bundle, as I have this just like you do) but it wasn’t so I just pulled the trigger on it & I can honestly say it is absolutely awesome, and does things I have never seen before in any other plugin – you can automate the mic positions in a way a real engineer simnply could not run around the room fast enough and there is no zipper noise at all!!!
Another massive plus is that it can be used in conjunction with other reverbs as well & things do not get all cloudy – it is mind blowingly good.