One thing thats been happening for a year or so now is that all BTC ITF organisations are opening their doors to other BTC ITF clubs. We regularily have UKTA train with us and almost all ITF style events, PUMA, TAGB, GTUK, etc are open to other organisations unless they are a specific "Closed" event.
For example the TAGB 25th Anniversary nationals are completely open to other ITF groups, I know quite a few GTUK people going.
Sounds like its going to be good. Hope its very rewarding for you!