Im no chemist so i couldnt say for deffinate from a chemistry point of veiw exept to say Id assume that the answer is yes, dependent on the concentrations of certain molecules.
From a physics aspect though, Id say yes, a higher salinity would make a difference. Generally speaking, the higher the density the smaller the bubbles that can be produced by a given pump assembly..(fill a skimmer with fresh water and you'll see what i mean)...with low density, bubbles are large, as you increase density you compress the same volume of air into a smaller volume, so the overal density of bubbles you can create for a given volume increases as you raise salinity.
would this be a good reason to increase salinity above normal levels...Personnaly id say no...The biological stresses an increased salinity level might cause on some organisms especially higher ones such as fish is imo not worth any marginal increases in skimmer activity gained
Regards