The trail was cold. There was nothing to hunt. Similarily, there is no sense having the best Jedi exterminator in the galaxy sitting on his ass on the off-chance a speck of a lead turned up.
If anything that could potentially point to important Jedi like Yoda or Kenobi, Vader would surely have dropped whatever he was doing and gone running after that.

But what threat was Yoda? He was in exile for like 30 years. He might as well have been dead, he did as much damage to Palpatines plans as if he had been.
Besides, if Palpatine was angry at someone with regards to Yoda, he would have been angry at himself. He was the one who fought Yoda and let him escape, after all.