Distant spell Link lets you use your companions Share Spells feature at close range, rather then touch.
Benefit(s): The range of your allied creature's share spells ability increases to close (25 feet + 5 feet for every 2 levels) as long as you have line of effect to the creature when you cast the shared spell. If your allied creature has the deliver touch spells ability, you can designate your allied creature as the spell's source when you cast a touch spell as long as you are within close range of it. The creature must still deliver the touch spell at its touch range.
Improved Spell-Sharing lets you split the duration of any spell you cast between you and your companion with only 1 cast.
Benefit: When you are adjacent to or sharing a square with your companion creature and that companion creature has this feat, you can cast a spell on yourself and divide the duration evenly between yourself and the companion creature. You can use this feat only on spells with a duration of at least 2 rounds. For example, you could cast bull's strength on yourself, and instead of the spell lasting 1 minute per level on yourself, it lasts 5 rounds per level on yourself and 5 rounds per level on your companion.
Because Distant Spell Link removed the need for you to be adjacent to your companion for the purposes of Spell-Sharing, would you need to still be adjacent to take advantage of the improved feat?