I've been wondering for a while now, has it been established how many of the new species introduced through the crewmembers on Titan are Federation members? I'm mainly asking about the Pahkwa-thanh, Syrath, and Choblik. I was gonna ask about the S'ti'ach, and Pak'shree too, but according to Memory Beta Orion's Hounds established that they are. I've been planning on reading the book again, but realizing that it gave so much background on the new species that I forgot about, makes me want to reread it even more.
I seem to recall that the Pahkwa-thanh have been UFP members for about 20 years. As for the others, it hasn't been established.
To quote your own novel Christopher, in reference to Alexander being the UFP's first ambassador to the S'ti'ach: "He had been pivotal in convincing the S'ti'ach that they could participate in the Federation as equals." I suppose it used the word "could", making it just a possibility, but that read to me very much like a description of a race who went on to be "in" the Federation, rather than just interacting with it.
I believe it is as follows (based on what has been stated or implied, so most of this is unconfirmed): Pahkwa-thanh: established member in "Taking Wing", admitted 2360 S'ti'ach: Probable member based on "Orion's Hounds" and "Losing the Peace" Syrath: Unknown- if they are a member, which is possible, "Over a Torrent Sea" established they're a reclusive one who maintain an enigmatic distance from other races. Choblik: My impression was a protectorate or ally of the Federation, not a member. Pak'shree: I don't recall much evidence for any particular interpretation.