Welcome to Vodafone Community
If you are a new PAYG customer the extra data will be added within 24 hours. The information you need is here: Summer Data Promotion on Pay as you go (1 July to 22 September 2021)
Have a word with customer services on 191 or Live Chat @mikeparkie
They'll get you sorted.
Also the Vodafone Social Media Team's via Twitter or Facebook can help.
I wish you all the best with this.
Current Phone >
Samsung Z Fold³ 5G.
Previous Phone >
Samsung Note 20 Ultra 5G - SM9860.
Assuming you and your Wife are new PAYG customers and are now renewing the BVB and need to opt into the promotion.
You should have received a text message as soon as the data was added. You will then use the core allowance first, when this has been used the promotional data will start and show on the Application.