Strange Matter "is a particular form of quark matter, usually thought of as a "liquid" of up, down, and strange quarks. It is to be contrasted with nuclear matter, which is a liquid of neutrons and protons (which themselves are built out of up and down quarks), and with non-strange quark matter, which is a quark liquid containing only up and down quarks. At high enough density, strange matter is expected to be color superconducting. Strange matter is hypothesized to occur in the core of neutron stars, or, more speculatively, as isolated droplets that may vary in size from femtometers (strangelets) to kilometers (quark stars)"
I have two question:
How would an alien species 1,000 years more advanced than us be able to create Strange Matter? A trip to the surface of a neutron star to obtain some is risky at best and suicidal at worst, so they have to find a way to produce a few grams of it.
How would you make a strange matter bomb? The biggest problem here is similar to how you would transport and use anti-matter. If the Strange Matter comes into contact with any matter, that matter will be turned into Strange Matter. Therefore I can not think of any plausible manner in which you could transport Strange Matter from factory to usage point so to say.
This is, however, assuming that Strange Matter does convert regular matter and that for some unknown reason it does not convert the entire neutron star into Strange Matter.