Is there a natural method for the widespread dispersal of banana plants?

Mostly it is done by fruit bats:

https://en.wikipedia.org/wiki/Fruit_bats
http://www.nwf.org/Kids/Ranger-Rick/Animals/Mammals/Fruit-Bats.aspx
http://www.seedman.com/banana.htm

Cultivated bananas have been developed not to grow from seeds(changing from diploid rather than triploid), but wild bananas do (it's the little brown bit at the tip of the fruit) hence the use of fruit bats for distribution.

Bananas reproduce by suckers, not from seed. They cannot disperse themselves, so the "natural method" of dispersal would be by humans taking them from one place and planting them in another. Bananas do spread a bit from their base, but without proper attention in keeping weeds and jungle down and hacking out old "trunks" they get swallowed up or degenerate. Recent guests of ours from Malaysia insisted the plaintain variety grows wild and uncultivated there. Perhaps this is true, but we doubt it; these were city folk.

Source: farming in the Amazon basin for twelve years.
https://docu.tips/documents/chemicals-needed-for-experiments-5c135e1724c12