This may sound like a noob question but....

[Hiwamari]

When a samurai grant his weapon expertise to Longbow, does it extend to his composite longbow as well?

[Jaunt]

Core wrote:

For purposes of Weapon Proficiency and similar feats, a composite longbow is treated as if it were a longbow.

[Scrapper]

It should extend given both weapons use the same proficiency. Also, over 500 hits for composite longbow can be found LOL!