Burial Equity for Guards and Reserves Act of 2021 This bill prohibits the Department of Veterans Affairs (VA) from establishing a condition for a cemetery grant that restricts the ability of a state to inter certain reservists (or their spouses and children) at a state-owned veterans' cemetery solely because such individuals are ineligible for burial in an open national cemetery. Specifically, as a condition for grants, the VA cannot restrict the ability of a state to inter a member of a reserve component whose service was terminated under honorable conditions; member of the Army National Guard or Air National Guard whose service was terminated under honorable conditions; member of the Reserve Officers' Training Corps of the Army, Navy, or Air Force who died under honorable conditions while a member; and spouse, minor child, or unmarried adult child of any member described above. The VA is prohibited from (1) denying an application for a grant solely on the basis that the recipient state may use funds to expand, improve, operate, or maintain a veterans' cemetery to allow for the internment of the specified individuals; and (2) enforcing certain conditions on grants for state veterans' cemeteries that were established before the date of enactment of this bill. The bill also provides for plot allowances for the individuals listed in the bill.