I just noticed the following: you asked me to write Tal Yan, while the NPC talks about the Tay`Yan. Will this be the reason why it didn't respond to Tay yan?
EDIT:
I just checked and, while the NPC wants you to write [Who are the Tay`Yan?], the correct spelling for the faction is Tal`Yan, so I guess that's why he wouldn't respond to my text.
I also would suggest changing "`" to " " in the green bracketed text to make it clearer.
Thanks.
EDIT:
Confirmed, the NPC answered to "Who are the Tal Yan". Future questers would thank you if you would fix this .