Nope.
My Theory:
Potara Fusion is based on the Potara-Earrings, so we have a specific magical power including. So with the potara it is possible to Combine two powers for a time, which is depending on the power. To say it mathematically:
(Power a + Power b) x time = Potara-Power.
The Potara power is a constant, means, the stronger the combination is, the less time they have for the combination. Extreme-Case, if the Power of a and b goes into infinity, the time will decrease to 0.
Fusion Dance is another case. The bonding here is no specific item, it is the strength of the participating People. So it is possible to Train the Fusion and Train the bonding, getting stronger and stronger and Keep the bonding, the Fusion alive. If the participating People of the fusiondance get strenth closely to infinity, the time doesnt decrease.
Summa summarum, the stronger the participating fighter are, the more gets the Fusion-Dance better than Potara Fusion.