On the BA Premium Plus Amex does anyone have experience if spend on a Euro denominated BA Holiday booking:

a) Counts as normal BA spend and so gets 3 Avios per converted GBP?
b) Counts towards the spend target for the Companion Voucher after conversion to GBP?

In my case I am starting in DUB with "flight tickets issued by British Airways, Dublin, Republic of Ireland" and the deposit paid previously in EUR.

Trying to work out if the Avios and making a significant dent in my spend target offset the terrible Amex forex fees.

Thanks in advance