A question on Death and Tiamat / Bahamut

[Dairuga]

Upon reading trough the fiendish codex; I stumbled upon an interesting passage. In particular, I came upon the statement that Nondragon Worshippers of Tiamat that dies incarnate as wriggling souls in her domain, and if she finds them highly worthy, she makes them into a white abishai.

Now, is there any information on what happens to a dragonic worshipper of Tiamat that dies? Or on the opposite end, is there any specified clause of what happens to a soul that worships Bahamut, after death? Dragon or otherwise?

[NOhara24]

I had read somewhere, possibly in the Draconomicon, that dragons souls become guards for an extraplanar dragon graveyard somewhere within the planescape. I'm not sure though.