SNAP Reform Act of 2021 This bill modifies eligibility under the Supplemental Nutrition Assistance Program (SNAP) with respect to individuals who receive other forms of assistance. Currently, households may be considered categorically eligible for SNAP if all members receive certain other assistance, such as under the Temporary Assistance for Needy Families (TANF) program. The bill specifies that members receiving TANF assistance must (1) receive at least $150 a month in cash assistance under TANF for an extended period with an income of up to 130% of the federal poverty level (FPL), or (2) be elderly or disabled and receive cash assistance or ongoing and substantial services under TANF with an income of up to 200% of the FPL. The bill also increases the maximum allowable resources for SNAP eligibility and specifies that certain allowances relating to energy assistance extend only to households with elderly members.