You will be so lucky if you find a whiles whale who will register on your personal links but I'm sure those guys knows how this referral earning works and for sure provably they will create a secondary account just to get those earnings for their selves(Just my opinion).
Doubt that this will happen. Im not sure about freebitco.in but having more than account is not allowed in many sites, let alone if you try to claim the referall bonus by using more than 1 account. Highly doubt that all those high roller on the site will be risking their account and deposit trying to get tiny rakeback from wagering
P.S : VPN might do the trick though 