Bootstrap messages distribute RP (Rendezvous Point) information dynamically during an RP election. They are also used to notify which router is the PIM RP. These messages are forwarded to all routers within a PIM sparse-mode domain, ensuring that the RP information is disseminated throughout the network. Therefore, the correct statements regarding bootstrap messages in a PIM sparse mode domain are that they distribute RP information dynamically during an RP election and are forwarded to all routers within the domain.