It's the Santander One bank account (in Spain). So, yes, the 4 euros per month comes on top of the Icon annual fee. This is nothing particularly new AFAIK.

P.S. Lots of fine print involved to determine if you qualify for reducing the monthly fee from 20+ euros...[/QUOTE]

I've been doing this since they launched it, it's now still 4E/mo but
- 100x2 avios/month instead of 250x2
One is for recurring income (can be self transfer from another bank, so free)
One is for direct debits (Openbank rebates 0.5% but only for utilities, so there is no opportunity cost in directing one's amex bill to Santander, so free)
So assuming 0.01E/avios that's 2E back...

- 25% bonus avios
I am a lowly Plata and not been able to 'double dip' the the 25% plata avios and the santander's 25%.
Moving on to the new avios earning structure, no idea if there still won't be double dipping, so just 6x for me, or 6x x 1.25x so 7.25x...
Assume worthless for now...

- 10% off flights
Used to work well, and it's 10% off the total fare, including tax and fees. But recently it's not been working, either the discount does not appear (even for vanilla IB flights), or the page errors out after selecting the discount
Defacto worthless for now...

- 1 avios/2E spent on free credit card
So amex gives 1/1 (1.2/1 during transfer promos), but not everywhere takes amex, and the amex gold is going to have a huge earning devaluation next year (down to 1/3 for supermarkets).
The other alternative is the Carrefour 1% rebate card but it does not rebate for anything Carrefour sells, so not supermarkets.
Simplistically, if one spends 400E on the card and get 200 avios, that's worth another 2E. assuming one spends the rest on amex and the amex fees are self-justified...

So....assuming one does the income & direct debits & spend 400E on the card one gets 400 avios which just about breaks even, assuming the 0.01E/avios valuation....