Yep, there are several tokenised stock issuers, and the biggest one, I believe, is xStocks.
Their products are not only on centralised exchanges, but also on probably a dozen of blockchains, tradable on the DEXes, and usable in other DeFi apps.
If the data in btc dominance chart include these tokenized equities as altcoin, it's no wonder the dominance is going down and the price decline of btc is rubbing salt in the wound.

I believe they are included, however, the tokenised RWAs marketcap is still only $10.24 billion as of now, which is less than 0.5% of total crypto marketcap.
FWIW, tokenised Gold accounts for almost half of it, which has been in a noticeable downtrend recently as well.
So short answer is no, RWAs on chain still have too modest of a share to affect the BTC.Dominance chart.