I wouldn't worry about bottle-necking. That rarely happens and when it does you don't notice it. That term is too commonly used. It's most popular reference is the Front Side Bus which does, in fact, act as a bottle-neck in the system.
The E6300 has a 1066 FSB, and is a 45nm Wolfdale which gives it significant overclocking power. You could probably top 4GHz with it.
I don't know your BIOS so I'll have to be a little bit vague in terms of where to go, but I can definitely help you on what settings to use.
Note there is a Actual Front Side bus (AFSB) Which is the REAL FSB speed and a Rated Front Side Bus (RFSB, or known as QDR - Quad Data Rate, for some reason) which is the Quad-Pumped FSB Speed.
If Core Clock = (RFSB/4)xMultiplier
Your multiplier should be 10x then.
If the desired Core Clock is 3.0GHz, then set the Actual Front Side Bus to 300 for 3000 = (300)(10) or It may ask for the input of the QDR or RFSB which would be 4x300 - 1200MHz RFSB.
Follow the same equation for other clocks.
For now, I'd leave the RAM at stock speeds to take advantage of faster timings.
And if your board has Auto-Voltage settings, I'd leave them alone for a small overclock.