With Dragonbone Bow, if you kneel the attached character to have them participate in the current military challenge, for example, if the attached character doesn't have a military icon can they still particiapte or must they have the icon to participate?

Same with Tyrion. Can a knelt clansman participate in a power challenge, for example, on the same side as Tyrion if the knelt clansman doesn't have a power icon?

Then also are the keywords in play from knelt clansman as well if they can participate in the challenege? Deadly, Renown, Stealth, etc.

A character only needs the appropriate icon if you wish to declare the character as an attacker or defender. Other effects that put characters into a challenge do not require them to have the icon. And yes, all the keywords on the Clansmen would count b/c they are participating in the challenge.

Bwhitt4691 said:

With Dragonbone Bow, if you kneel the attached character to have them participate in the current military challenge, for example, if the attached character doesn't have a military icon can they still particiapte or must they have the icon to participate?
They can still participate.

As Skowza indicated, icons are only prerequisites for being declared as a challenger during the framework action that allows you to declare attackers. A character without the appropriate icon can not be declared as an attacker (or defender) during the framework action, but can enter the challenge by other means regardless of having the appropriate icon.

Can a knelt clansman participate in a power challenge, for example, on the same side as Tyrion if the knelt clansman doesn't have a power icon?
Yes.

Then also are the keywords in play from knelt clansman as well if they can participate in the challenege? Deadly, Renown, Stealth, etc.
Yes.