We believe that there are ordinances in which one must participate in order to obtain Eternal Life. The first of these is baptism by one having authority. Others occur in the temple.
Not everybody gets the chance to participate in these ordinances in life; that’s why we perform vicarious work for those who are dead. It’s a testament to the justice and love of God - nobody is barred from Him on account of never having the opportunity.
As to your question, the Law of Tithing is one of the laws that must be obeyed in order to worthily enter the temple. Other such laws are the Ten Commandments, and the Word of Wisdom. If I am a liar and cheat, then I am not worthy. If I am a thief or adulterer, then I am not worthy.
The point of the temple recommend is a sort of “certificate of worthiness.” This worthiness means obedience to the Gospel - including the Law of Tithing.
One great aspect of the temple recommend interview is that it gives you an opportunity to ask the bishop for help and council in solving those things in your life that aren’t right. In the end, the bishop is not an executioner; he’s a servant.
Sounds like a bill to me.