The only way to be made whole throughout the contract is for the full-time drivers with seniority dates before August 1 is to receive their progression rate and a separate GWI compounded every year until they hit 48 months and then go to top rate.
Where does it say it gets compounded? The rates for full timers in progression are pretty clear. If this grievance is settled in favor of the membership at all, my guess would be that drivers in progression could be entitled to the contractual raise on August 1st, then go up to the next progression rate on their anniversary. I doubt that will be the case because it would be inequitable for the grievants, some would receive a raise for longer than others based on their anniversary dates. I hope, for your sakes, that I am wrong and everyone gets even more money, though the $3/hr bump you are already getting is pretty nice on its own. Best of luck, and please do keep us up to date.