Yeah they are. Buses are a super cheap way to get around, if you don't mind a booger in your ear then go ahead and use them.

Russian buddy of mine uses Greyhound busses all the time. Says nice things.

I'd download some movies and shows at home on the netflix app or other wise.

I took a groundhound bus once and they told me that their was wifi but the wifi on the bus didn't for some reason.
I would suggest downloading music to your phone so u can listen to it and also games.
But if you have a game boy or something I would suggest bringing that with you.
I also would suggest buying a portable phone charger that way if your phone died u can just plug it in and charge it without having to plug it into the wall.

I've used one before it was really comfy and the wifi was decent out here in cali.. but they make alot of stops which kinda got annoying lol