Cell phone charging outlets on the bus?

Maybe.

Probably not universal, but becoming more common.

Many buses have them, and most of them seem to work but not all.

Rick Steves tour? As Joe said “maybe.” Check with Rick Steves tour office.

To be safe, always carry a power bank.

On our Best of Turkey tour (2022) there were not charging outlets on the tour bus. Maybe there are now.

You are probably better off bringing your own powerbank.

I've been on coaches that have them and some that don't. I remember one had one central area with USB plugs but only a few of them. If you weren't first, you didn't get to charge your phone.

Bring a powerbank. I always have one for plane, train, bus and even car journeys. You never know if the outlets will work.

Agree with bringing a powerbank.
I bring a very small one just to top up during the day.

Rick Steves uses local companies for their buses, so there are differences in amenities.

Thank you to everyone that replied. I'll purchase a Power Bank just to be safe. Safe Travels!!!