Sharing between different iTunes accounts
One Computer must activated for a specific iTunes Account. Once the Mac/iPad/iPhone/AppleTV is activated, you have to wait 90 days to switch the account.

For example: If your Dad has activated iTunes Match, he has to wait 90 days till your wife can activate iTunes Match on the same device with her account.

The solution would be to carry around your iPad and stream it from there. 


  There is no sharing between iTunes Accounts. So currently you have no
  chance to transfer all music from one account to another.