Answer:
Currently (assuming a 2020 tax schedule), Scott and Vidia's tax liability = $29,211 + [24% x ($246,000 - $171,050)] = $47,199*
municipal bonds are not taxed by the federal government, so they do not pay any taxes on the interests earned on the City of Tampa bonds.
if they earn an additional $81,200, then their tax liability will be:
$66,543 + [32% x ($327,200 - $326,600)] = $66,735
their marginal tax rate = 32%