@Feurbarb,
In this context "recommendation" is basically synonymous with "advice." It is being "given" to somebody, not "for" somebody.
So, in my opinion, "to" is better, although using "for" would be easily understood. Actually, if you used "advice" rather than "recommendation" then "for" would seem more appropriate.
Not sure I can explain why. Maybe it's just the way those are commonly phrased, with no hard "reason" behind it.
If I was forced to give some reason, right or wrong, I would probably say that, as a rule, "advice" is treated more like a helpful suggestion, whereas recommendation is more in the form of a quasi-demand. You give advice "for" somebody to consider. You can give a recommendation in such a way that's it's deemed to be an imperative--an "or else" proposition.