Al Hanissim in Al Hamichya Part 4

I hate posting on the same thing over and over again... but I finally found the Brisker Rav's answer inside (see this earlier post). The Griz is, in fact, found in the back of the Griz Al HaTorah (as a commenter pointed out to me). Here is a rough translation of what the Griz has to say:

It needs investigation why we do not mention on Chanuka and Purim Al HaNissim in the Bracha Me'ein Shalosh. And it seems, because Al HaNissim has no "din bracha" on it, and it is only a mere hodaah, and in the bracha me'ein shalosh there is only room for a bracha, and for that reason we don't mention in it Al HaNissim. And that which we mention Retzai and Rosh Chodesh in the Me'ein Shalosh, we need to say that there is, in fact, a "din bracha" [on them]. And the proof of this is from that which we say in the gemara that if one forgets and doesn't say Retzai etc. he says after Bonei Yerushalayim and ends with a bracha, so you see that there is a din bracha, and it's not merely a hazkarah. And according to this it is also explained, that because the only reason that we mention Retzai in the bracha me'ein shalosh is only because it is a bracha, and since the whole din bracha of retzai is only after bonei yerushalayim, and that is when you forget to say it on shabbos in its right place, so therefore its place in the me'ein shalosh is after bonei yerushalayim, since the whole din bracha that it has is only after bonei yerushalayim. - Grach

I think that the answer given in that weekly torah publication that I posted here was taken from this Griz but written in an abbreviated fashion.