Here are the relevant BalancerLabs LPs eligible for Aave staking.

- WBTC/WETH: https://pools.balancer.exchange/#/pool/0x1eff8af5d577060ba4ac8a29a13525bb0ee2a3d5/

- BAL/WETH: https://pools.balancer.exchange/#/pool/0x59a19d8c652fa0284f44113d0ff9aba70bd46fb4/

I figured it out from the Aave URLs. i.e. The Aave market URL for WBTC/WETH reveals the corresponding Balancer pool address.

URL: https://app.aave.com/reserve-overview/BPTWBTCWETH-0x1eff8af5d577060ba4ac8a29a13525bb0ee2a3d50xacc030ef66f9dfeae9cbb0cd1b25654b82cfa8d5

Balancer LP Contract: 0x1eff8af5d577060ba4ac8a29a13525bb0ee2a3d5