can you get commendations like weapon commendations or gametype commendations in custom games
Simple answer:
No.
EDIT: However, you can earn the Wheelman commendation in custom games.
> can you get commendations like weapon commendations or gametype commendations in custom games
No.
However, playing solo spartan ops ups your enemy commendations for that,
Custom games cannot raise commendations, however Spartan Ops can raise certain ones. These include many Vehicle commendations, including Wheelman, Banshee Destroyer, Wraith Destroyer, and Ghost Destroyer.