Depends how you define bubble. Let's use this:
stocks have very simple fundamentals you can use: dividend yield. If you have a low dividend yield, and low earnings growth, then that would be a bubble. If you have a low dividend yield and high earnings growth, that would not be a bubble.
Real estate is not a bubble because:
1. Interest rates are low, and banks are still lending
2. They refuse to make more real estate!
Interest rates change the calculations for both of these. If the cost to service debt increases, then company earnings can decrease, real estate becomes less affordable and if prices do not adjust, they become bubbly.
That's why everyone is looking and hoping that Powell pulls a rabbit out of his ass and doesn't need to raise interest rates. Mark my words: they will not increase interest rates.