I believe it's tick rate based as wellWatering can is a tick rate thing, while I'm not sure what the lamp of growth is. I know it produces green sparkles, but it doesn't always make it grow so I'm not sure which it is.
Tons of things can speed up Magical Crops growth. Thaumcraft Lamp of Growth. Blood Magic Sigil of the Green Grove. OpenBlocks Sprinklers. Agricraft Sprinklers. Rotarycraft Sprinklers.
So far as a manual bonemeal for a 3x3, a XU Watering Can is the closest I can think of.
I think the reinforced watering can works in an autonomous activator.
It does but it's crazy expensive.