Bone meal takes time to break down properly in the soil for the plant to digest, so top dressing with a teaspoon won't show effects immediately -- even with watering. Usually you'd mix it in with the soil prior to filling the pot (some people even mix the soil and leave it for a week or two prior to use), so the plant can absorb it effectively.
If you need to see more immediate results from fertilizer, like if your plant isn't doing very well or you are growing autos which can't wait around for the fresh bone meal to break down, than liquid fertilizer with micronutrients that you can add directly to the water would be a good solution. You can get some 5-15-5 for around $10 at your local home gardening center. Just use it at 1/4-1/2 strength (depending on your specific plants -- look up the strain and see what is recommended).
I'd recommend something with root stimulator, too. Really help develop those root structures early on.
Check this out (link).
Speaking of which... don't be too generous with watering during veg. Let the top of the soil dry out a little first, usually about an inch or so down. If you water too much during veg the roots won't have to grow as much to 'seek out' water, which can lead to a shallow root structure later on. Generally speaking, the time to increase watering is mid-way through the grow when the plant starts sucking it up like nobody’s business.
I hope that helps.