It is in fact possible to get full Google Now functionality in a Google Apps domain. I've had it working for a long while.

Go to the Google Apps Admin Console (https://admin.google.com/AdminHome).

Navigate to Apps > Additional Google Services

You'll see a gray bar at the top of the screen ("Filter: Top featured services"). Click the "X" on the top right to disable that filter.

Scroll down to "Web History" and select "On for everyone."

Each user may then need to also enable Web History for his or her own account (https://www.google.com/settings/accounthistory/search).

No, it shouldn't be that hard, but, yes, that will work.

I have never been able to get email based cards for my domain account.

How did you set it up?

Instructions are at https://support.google.com/websearch/answer/2938260?hl=en. Even though the setting is under Android Settings it does also enable Google Now for iOS.

I've heard this before, and as far as I can tell it isn't true. There is an option buried in Device Management that claims to turn on Google Now for Android users but the service it enables is a subset of the full capability of the product. Namely, you get no cards based off of your email inbox. No flight notifications, package tracking, and similar things.

I do.