Yes, betta fish can live with bristlenose plecos. Even though bettas are notorious for being highly territorial and aggressive, they’re unlikely to attack bristlenose plecos. As bottom-dwelling fish, bristlenose plecos won’t get in the bettas’ way, so conflicts are unlikely to happen.
Just make sure to get a tank that’s large enough to accommodate them. A single bristlenose pleco requires at least 25 gallons of space and a betta needs at least 5 gallons of space.
Lastly, don’t forget to stock the tank with plenty of live plants and hiding spaces to prevent territorial conflicts.
With that said, you can also consider more peaceful fish to be your bristlenose pleco’s tank mates, such as: