I cannot see any other correct meaning other than RPM unless you include spin axis but I doubt that is part of it.I see this phrase used all the time, 'tight spin'. I assume it means high RPM spin, but maybe not. If there is another meaning could someone explain it?
Since my comment seems to be the inspiration, yes, you nailed it. The perceived wobble = not tight, so my definition of tight would be a high RPS with proper seam orientation. If the pitcher is holding the ball correctly she should be able to spin it so the tape doesn't "wobble." The axis may not be 100 % correct, but the spin could still be "tight." That's why the tape help us see what's happening since it's showing the seam orientation.Spin axis is not going to change or wobble, once the ball is released the gyroscopic effect will keep the axis steady. It's easy to get fooled when you see a ball with a stripe on it that wobbles, it makes it look like the spin axis is changing, what's really happening is that the stripe is not aligned with the spin axis. The video posted in the "Pitching Gurus" thread is an example of this.
Seam orientation is not easy to discern on a spinning ball.
If it is high RPM then you would think there is a better word to use than 'tight', I'm not sure what it would be. It really doesn't matter as long as everyone understands what it means.