Can using Sticker GO lead to restrictions or bans on Monopoly GO?

Absolutely not. Sticker GO and Monopoly GO are two separate and non-integrated platforms. Sticker GO provides a system to help users find others for sticker exchanges; it has no access to or influence on Monopoly GO’s systems.
It is impossible to receive a ban on Monopoly GO due to the use of Sticker GO, as the two apps are completely independent. Your Monopoly GO account is therefore safe and unaffected by your use of Sticker GO.