Dave: I got some progress with that. If you want, you can send me your files and I will have a look.
In short; intelligence is crucial to trigger anti-ship strikes. Soviets need to know about the convoy to hit it ! In NA, you are shooting down Recce flights for that reason. If you raise the Intelligence of the convoy, the Soviets will know of it. I tested it at 100; and Task Forces was attacked on the first mission. Its either raising it or giving the Soviets A LOT of Recce flights as one is just not enought to raise the intelligence that much.
If you want the abovementioned result; I would suggest a limited operation time for the bombers. After that, Ground Forces spawn. Depending on if you want other flights avalible; you can spawn squadrons that attack on land then. If you want them flyable; that part is trickier but should work with the RunCampaignBeforePlayerStart=TRUE command.
This is all guesswork tought.
http://combatace.com/topic/71346-sf2-na-naval-combat-3rd-party-campaigns/
Second post displays what I mean. However - and this is interesting; I seem to be unable to participate in Naval Strikes myself. I am simply sent off the map. An error with my water map perhaps?