More loft and axis rotation can mean more of a hook down the lane.  However, you should be careful in making span adjustments just for the heck of it.

One should keep into consideration the type of lanes one bowls in, as well as the conditions (oil patterns, etc)

More importantly, a lot of drillers have been advocating a more relaxed span (shorter spans) for typical league bowlers to avoid excessive force on their fingers which leads to injuries.

Years ago, the fad for bowlers was to go to extreme finger tip spans.  Some 'newer' spans can be considered to be a semi-fingertip setup today.

This is where a good coach - someone who will be familiar with your throwing style as well as your typical conditions is invaluable.