"John B" or John K asked:

"Does this mean that smaller bass swim faster than larger bass? grin"

The swimming speed of largemouth bass has not been studied in depth and I
have not seen any research publications on the subject. Some scientist once
told me that bass can swim at 2.5 times their body length per second. That
means that small bass can swim about two miles per hour and a 20-inch bass
may swim in spurts up to 12 miles per hour. Bigger is faster.

Since science says smaller bass DO NOT swim faster than larger bass, the
events you observed must be caused by some other facts. Smaller bass "can"
swim faster than larger bass, especially when scared or when being casually
pursued by a not so desperate larger bass. My guess is that there is some
other explanation for the difference in size of bass you were catching. If
you can discover why the size difference, my guess is that this group would
be interested in your findings.
Good Luck!
John