I'm in the midst of an archive trawl(!) and certainly up to the end of "Soul and Squoddle" he has no idea. This strip is the first time someone has actually told him of the subject.
The thing is, it's never been made entirely clear whether Bruno is the descendant of Ailix (as
originally claimed by the Bluebird) or a direct descendant of a
clone of Ailix (as
claimed by Brother Maynard), or that the whole thing was just cooked up by erstwhile Bunkleyutzes (according to
one of the Opus Knights).
As per
this strip:
Eunyce: ...does Bruno have the potential to be the new messiah?
Ailix: Yes... yes he does...
Note: this is not the same as Ailix stating that Bruno is his descendant, merely that Bruno could be his messenger.
This strip agrees:
Eunyce: Our son is going to be the next messiah...
Ailix: Whoa there! I never said that!!
Ailix: Your son has the potential to be like me... as does everyone in this room... indeed, everyone in the world!
Ailix: A misconception is that I shall return to Earth one day, to make everything right! Even my own wife, the Amissus thought so! The fact is, "I" will return, in the form of Ailixists acting according to my example. Is that so difficult to understand?
I think the truth of the matter is that the Bunkleyutz line is cloned from Ailix, thus preserving the "descendant" claim without being a true descendant in the normal fashion. That's what I make of it, anyway. Of course, only Ian can tell us for sure...