Rare B-meson decays are powerful probes to test the Standard Model (SM). Recent measurements of several observables in both $b\to s ll$ and $b \to c l \nu$ transitions have shown tensions with the corresponding SM predictions. These tensions between theoretical and experimental results are called B-anomalies.
I provide improved SM predictions for the exclusive rare processes $B \to K^{(∗)}\mu\mu$ and $B_s \to \phi \mu\mu$. My predictions have, for the first time, controllable systematic uncertainties due to the usage of a dispersive bound. Comparing my predictions within the SM to available experimental data, I find a large tension for $B \to K\mu\mu$. A simple model-independent analysis of potential effects beyond the SM yields results compatible with other approaches, albeit with larger uncertainties for the $B \to K\mu\mu$ and $B_s \to \phi \mu\mu$ decays.