Yes, the bank knows that. We bought a plot of land from the family at the standard land value, but in fact (and also as set by the bank) it is worth twice as much.
It all depends on the bank. It can be: a) that the standard land value is taken as the property value b) the "market value" is taken as the property value c) the payment amount is taken as the property value
Therefore, you always have to compare. In our case, it would mean: payment amount: €58,000 vs. market value: €200,000