Hi colinfromnorth bendigo,
Welcome to the Apple Support Communities! I'm sure we can help you out with your question, or at least get you pointed in the right direction. While there is no way to transfer purchases between Apple ID/iTunes Store accounts, you and your partner may want to look into the sharing options available with Family Sharing, which does allow sharing of content between accounts. You may find the information outlined in the following articles helpful:
Share purchased content with Family Sharing - Apple Support
iCloud - Family Sharing - Apple
Regards