VC dimension of polynomials (in one variable) of degree d
The basic method works like this: Assume your inequalities are of the form 

$$ \sum_{i \le d} a_i x^i \le 0$$

Then you construct a lifting map to a space of higher dimension in which each monomial corresponds to one dimension. Now the polynomial can be expressed as a linear combination of the new dimensions and you can invoke the usual result for half spaces in the resulting space. 

I'm not sure where you get your bound from: the correct expression for the VC dimension of polynomials in d variables of degree D is $\binom{d + D}{d}$, which is the number of monomials of degree at most D formed from d variables.