Well, existing stealth bombers (basically B2 at this point) are sub sonic while many fighters are super sonic.
As for range - that's a good point, if your low fregvency or passive radar gives you a big bounding box, your fighters could run out of fuel before they find the stealth bomber. Or it might drop/launch its payload before you catch it.
Supersonic dash capability can help in some limited circumstances but it doesn't fundamentally change anything. Fuel consumption at those speeds is extremely high.
As for range - that's a good point, if your low fregvency or passive radar gives you a big bounding box, your fighters could run out of fuel before they find the stealth bomber. Or it might drop/launch its payload before you catch it.