I have an article that may help you with this question:
You can start new stations based on artist, track, genre, or sub-genre. To start a new station, tap the Plus ()button under My Stations. When prompted, type an artist name, track name, or genre or select a genre from the list. When creating stations by genre, iTunes Radio will play six second preview snippets for you prior to selecting a genre. Once you've decided on a genre, simply tap the Plus () button to the right of the genre name to create your station. You can modify your stations while listening to them by using the Star (✭) menu to play more like this or never play songs like this.
You can customize or edit your stations while listening to iTunes Radio. Use the Star (✭) menu to play more like this or never play songs like this during playback. In addition, tap the Info () button to fine tune your station even further.
To edit your station:
- Tap Edit to the left of My Stations.
- From the resulting pane, tap on a desired station.
- Tap the Plus () button to play similar tracks by artist or track name on your station, or you can choose to never play tracks by artist or track name.
- Click the radio station's name to customize your station's name.
Take care, and thanks for visiting the Apple Support Communities.
Braden - you do realize that that very helpful article does not discuss what the OP wants to do?
As far as I know - in my limited usage of iTunes Radio - there is no way of blending/mixing multiple radio stations - though I think this is something that Apple should consider adding in the future.
While there is currently no way to directly combine two stations (as far as I know), there is a workaround which should give you the same results.
What you would want to do is manually copy the artists/songs/genres from the "Play more like this" and "Never play this" lists in Station A to their respective lists in Station B.
At that point, Station B will be your "blended station" and you can delete Station A.