In some Native American cultures, the symbolism and choice of plants, flowers and herbs varies based on the specifics of the local environment and traditional practices of individual tribes. While there may be cultural importance and significance given to specific plants or herbs in general, the use of bean plants specifically for the purpose of an ending dance ritual in wedding ceremonies is not commonly mentioned in documented information about Native American wedding customs.
If there is a particular cultural context or setting where bean plants play such a role, you may wish to consult reliable sources of information on that specific ceremony or wedding tradition to understand its unique symbolism and significance within that particular cultural framework.