Not necessary to change the community to Star, but I'm sure you will need to have CompA subnets in your encryption domain. If not, your gateway will drop encrypted packets destined to CompA coming through the CompB tunnel (you'll get a log entry saying encrypted packet should be clear text).
You will need to double-check that your firewall routing is correct, also the CompA network will need to route return traffic via your gateway. Anti-Spoofing on the internal CP interface might also drop return traffic, so keep an eye on that.