As this seems to have been much the more important of the two Trebula (the other being Trebula Suffenas), it is probably that meant by Strabo, who mentions Trebula without any distinctive adjunct but in conjunction with Eretum.
Given that Trebula seems to have been the more important of the two locations, it is likely that Strabo intended this one when he mentioned it without any additional details but alongside Eretum.