You can track on the BTC blockchain, and on the Waves blockchain.
When you swap BTC for wBTC, if think you can easily guess with the amount sent.
eg.: I send 1.4458BTC to the gateway, I receive 1.4458 wBTC. The link is easy.

So I don't think you can stay anonymous that way.
To stay the most anonymous, and blur the link between blockchains, you must use the Monero gateway. Only the gateway will know about your account, but peoples won't be able to track.