Bi-wiring?

A friend gave me a pair of meadowlark kestrels hotrods. There are 4 post on back of the speakers, 2 for tweeters, 2 for bass woofers. How is bi-wiring done? I have them piggybacked from +tweeter to +bass, -tweeter to -bass. Any harm in wiring them like this? If so, how exactly does one bi-wire? Thanks in advance!
Ddjr