Pretty much all Ilex can be used for bonsai. However Ilex aquifolium is not very popular for bonsai. It can be used, has been used, and will probably be used by others. But it is not real popular. The main reason is the leaves are very stiff, and tend to point in many directions. The leaves do not lay out horizontally. Some point up, some point down, some are horizontal, the jumble of leaves pointing in many directions means the tree usually looks dishevelled, untidy.
But with judicious pruning, you can make a fairly nice arrangement. Eliminate the leaves that are obvious in the way they stick out. A second problem, is the leaves are slightly on the large size if you try to make smaller bonsai sizes. The leaves reduce, but not as dramatically as with some other species.
A third problem, Ilex aquifolium tends to have somewhat coarse branching habit compared to other Ilex species.
But all in all, Ilex aquifolium is not the worst species. And when displayed in winter with berries it makes a lovely image. If you have one, go ahead and try to make bonsai with it. I would not spend a great deal of money to find one, but if you end up with one go ahead and work with it. It can make a "pretty okay" bonsai.
Better species of Ilex to use for bonsai are Ilex verticillata, Ilex serrulata, Ilex glabra, and Ilex vomitoria. These species are either deciduous, or they have smaller leaves. In Lebanon, Ilex vomitoria might be the best choice as it has small leaves and is evergreen. It should be fully winter hardy in Lebanon.
