You don't need to go that early for the jersey I don't think. Definitely do for the bobblehead. But either way, you don't really have to "line up." As long as you get there around the time that gates open, there's no way you'll miss out on a giveaway.
The lines move so fast that I haven't had to "wait in line" at any point this year except Opening Day, which was only about a 5-10 minute wait before we were in. And once you're in the stadium there's lots to do. You can grab food early, you can take a look at the Authentics shop, you can watch batting practice, visit the flight deck, etc.
Springer jersey day the gates should open at 1:30 PM (1.5 hours before the 3 PM start time). Vlad and Dad bobblehead day is a weekend so the gates should open 10 AM (2 hours before 12 PM start time).
If you're there for the time the gates open, the line floods in and there's no real wait, especially if you go to one of the less busy gates. Both games are still early enough in the day too that you have plenty of time after the game to experience the city and plenty of daylight to visit parks.