CDG to Paris - Roissey Bus

No.

No, they are separate entities. Just wondering why you wouldn't use the RER to get into Paris, especially since you need to use the Métro to get the rest of the way to your hotel anyway. Your RER ticket will also extend to the Métro system once you've arrived in Paris. My wife & I used the RER to CDG when departing Paris. There was even a strike on at the time! In spite of this, we still got to the airport easily and quickly. (Originally we thought we'd have to use the Roissybus; this turned out to be unnecessary.)

Where exactly is your apt? You'll possibly get better responses if we know exactly where you're going.

Skip the bus and take the RER into Paris. It is faster, will not get caught in traffic jams and it links you to the Metro.

JIm, What is the address of your apt or what is the closest metro station?

Yes. RER train to the Metro line that takes you to your apt.
The combo of RER & Metro is an easy way to navigate Paris. You can find a map of all the lines online. Or in the RS Paris guidebook. Joan

If you travel light the RER/metro is the way to go. In my 2 days in Paris I have seen a lot of tourists struggle with luggage as most of the metro's have a lot of steps to get up to the exit along with the RER. I am staying next to the Porto Maillot metro which has many steps to get to the outside. I took the AF bus which costs 24 euros round trip and dropped me off across the street from my hotel Le Meridian Etiole. They even load/unload your luggage for you.

Have any of the people suggesting the train is a better option actually tried the bus? It is as easy as easy gets. Traffic is the only downside, but Sat and Sun are quiet, and even during busy times it makes decent time. There are no stops and you get a view as you drive in.