Originally Posted by JDC
You can run your vent across the basement as long as it rises at least 6" above the flood level rim of the highest fixture served (most likely your vanity) before it turns horizontal. Your horizontal run needs to pitch back toward the bathroom...rising as it goes across the basement to the existing vent tie in.
As far as the local vent on your ejector, check with your local building dept. Here local vents have to run out of the house by themselves.
Couldn't have said it better myself.
I'm not really sure what the reasoning is behind the ejector vent going out separately.
P.S. I always put grade on my vents, but we're technically allowed to have them flat. I find it easier to give it some grade than trying to make it perfectly level. Especially if you're using ABS, it's almost impossible for any length of pipe to have perfect grade unless you're strapping it to a beam every 12".
It's getting late. I'm rambling. Goodnight.