Hi Kimberley,
What an eventful trip to Walt Disney World you had! Congratulations on your engagement, and please let me be one of the first to say "Welcome home!" to Disney Vacation Club. You have many years of magical vacation memories ahead of you!
When you purchase a Disney Dining Plan for a Disney Vacation Club reservation, you do need to purchase it for the length of stay for all guests on your reservation. So you and your fiance would need to both purchase a Dining Plan.
Let me offer you another option in regard to Walt Disney World dining, one which my family has taken advantage of for years. As Disney Vacation Club member, you are eligible to purchase a
Tables in Wonderland card. This entitles you to 20% off of food and beverages at many Walt Disney World dining locations. For Disney Vacation Club members, the card costs $100. My family and I have found that Tables in Wonderland is a great deal for us. For more information on Tables in Wonderland including participating restaurants and how to purchase the card, please visit the website that I provided earlier in this answer.
I hope that these thoughts are helpful for you, Kimberley! Congratulations again on your engagement and on joining Disney Vacation Club. Please do let us know if you have any further questions!