No, the Black model does not require this relationship to hold. For example, futures on currencies exhibit a different relationship between the future and spot price because of the interest debit/credit nature of currency borrowed/lent. However for the Black model on European futures options to hold the following condition has to be met:
The product of the asset price probability distribution and the pricing kernel
has to be log-normal.
It can be shown that the asset price probability distribution does not necessarily have to be log-normal but the above has to hold to price, for example specific stock options (such as European spot options), bond options (where bond prices are log-normal), and some of the interest rate options (where such interest rates follow a MSS-BGM process). The Libor Market Model (LMM) is actually just a special case of the Black model.