Increasing the motor supply voltage while using current limiting like the A4988 provides does increase maximum pulses per second a stepper motor can handle because a higher voltage causes the coil current to ramp up more quickly. There isn't an easy way to know how well your stepper motor will respond to an increased voltage because it depends on the construction of your particular motor.
I recommend testing your motor under the loads you expect to see in your application with different pulse rates to see what actually works in practice. Also, keep in mind that you can often achieve higher speeds if you slowly and smoothly ramp up the stepper motor speed.
Also, as JIm Dearden points out in a comment, if you do not increase the pulse rate, the stepper motor will go the same speed whether you use 2.7 V or 12 V for the supply assuming it moves in both cases.