Further to that, planting a tree costs 1$ for individuals at organizations like onetreeplanted. I assume that in Bulk it is much cheaper, let's be generous and assume it's €0.50, although most probably it's even less.
So now I order the bunq green card and pay €99 for it for one year. In trees, this would be 198. Now I start spending using my green card. Let's assume I use it quite a lot and spend €1000 with it a month. 10 trees planted. Makes 120 a year. So this way bunq even makes money out of my "donation".
-> No value for me. No value for the environment. Sorry, as much as I like bunq and as much as I would like to support something like this: No.
If you want to plant trees, use Ecosia instead of Google. I switched to it at my office computer a couple months ago and had more than 800 trees planted by using it. This is innovative. Selling a super-expensive metal card with no additional value by calling it green and donating a bit of it's price is not.
Further to that, I would even go ahead and say this is a mockery on those who seriously want to do something for the planet.