When I contacted AT&T last week, the Rep told me that no corporate discounts apply to the new iphone.
She said that if the iphone were the secondary line on the family plan, I could still get the corporate discount by
1. changing the current secondary line to the primary on the account.
2. adding the iphone 3G as the family share $9.99 line.
3. The full data plan is required for the iphone and that will not be discounted.
So she switched the accounts over the phone and I'm ready for 3G.
By the way, she said that it's $199/$299 for everyone who has an account in good standing, regardless of eligibility for an upgraded phone.