How would you play this? I think I generally understand how ties work but I'm a bit confused by the marked articulation. Would you hear a distinction between the two notes?
The tenuto bar concerns how long you hold the complete note. It does not affect the tie. However, here are several indications that this is not actually a tie: first ties are usually much flatter and shorter. Second, it would be rather unusual to split a half note up in that manner unless the second of the tied notes falls on a strong subdivision of the measure (there is too little shown to know whether this is the case).
On instruments where the slur indicates some detail of technical execution, like on a bowed string instrument ("don't reverse bow direction"), a tenuto bar may indicate detachment, but only so if it is placed on the first of the tied notes. If that is done, most commonly the second of the tied notes also gets a tenuto bar when equal articulation of both notes is desired.
As written, and assuming a tie rather than a slur, the tenuto bar indicates how a note of four eighths of length is supposed to be articulated at its end.