Well, this doesn't work as expected. As long as I don't get this straight this will just be a collection of links and hints.

New contact entered on BlackBerry Device, took two minutes to sync with groupwise address book, entry show in GWPA log shows "NEW CONTACT"

Creating new contact in GroupWise client doesn't sync straight away

Disabling Wireless Sync on address book and re-enabling it doesn't do it straight away.

Toggling on and off the address book sync in PIM sync properties in BlackBerry Manager doesn't do it straight away either.

Restarting the BB Device didn't do it either lol (i had to try it)

so it looks like the sync will wait 4 hours as mentioned before new contacts are present on the device.

I did some of these tests as well and have to admit that above statements are true as fas as I can acknowledge.