For a bandpass transfer function, are there two gain bandwidth products?
If you're asking about an op-amp based active filter it's because the op-amp GBW product doesn't really restrict the bandwidth of the design. It restricts the highest frequency the design will be able to pass.

So even if the design is an HPF, the op-amp's GBW product will restrict the maximum frequency the design is able to pass. 

Or if it's an BPF, it restricts the maximum the high-frequency cut-off of the filter can be and still operate according to the usual design equations.