I don't think either IC normally have rates including airport transfer, and even less likely to have complimentary ones.

Both IC are served by the airport limo bus service, we took the Korean Airline branded bus service from the IC COEX to ICN, and it made a stop at the IC Grand to pick up more passengers, the cost is around KW14000.

The Grand has a lot of suites, and would most likely provide a suite upgrade even to standard Ambassadors. IC COEX rooms are much smaller, and very unlikely to get upgrade rooms, but at least you will get the perks listed at the top of this thread.