Raisin Tree is often labeled as being hardy down to Zone 5 or 6, but it appears Zone 6 (0 to -10F) is more accurate. Its native range also supports this view. Hebei (Hopei) is the coldest Chinese providence this species is found in, and most of it resides in Zone 6 or warmer. For comparison, most of Hebei's major cities have average high and low temperatures similar to Philadelphia during the grow season (roughly 180-210 frost free days with an average July high around 86F).

During the winter of 1975-76, two newly transplanted raisin trees, probably around 7 years of age, died back to the ground at -10F around Newark, Ohio. They re-sprouted and grew well but died out after experiencing -23F temperatures the following winter.

In Philadelphia, a large tree died back to within a few feet of the ground after experiencing winter temperatures that were supposedly as low as -17F in 1934, but it re-sprouted and grew well for many decades (Philadelphia had a record low of -11F in 1934, perhaps it was colder at the Arboretum where the tree was planted). The tree may have only fruited twice during a period of 40+ years.

Boston is the coldest known location raisin trees have fruited. In 1978, one of its two large trees began to flower in mid-JULY and ripened a large crop in October. This tree had been exposed to full sun throughout its life. The tree that did not fruit was partially shaded. It did not mention how often these trees fruit. For comparison, Boston has an average of roughly 170-180 frost free days and an average July high of 81F (In 1978, when the tree fruited, the average monthly temperatures were normal). Any location cooler than Boston will probably never be able to ripen fruit without an improved cultivar (no known cultivars exist at this time) considering the amount of heat required just to open the flowers.
Seedlings can fruit in as little as 3-4 years if planted in the right climate and location, otherwise it could take up to 7-10 years.
Raisin Trees prefer well-drained soils, but they can tolerate excessively dry or moist soils better than most other fruit trees. A wide pH range is also tolerated, but they prefer it neutral to slightly alkaline (6.6 - 7.8).
Additional Reading
Raisin Tree Hovenia dulcis
The Raisin Tree - Its Use, Hardiness and Size