Doubtful. From what I've seen there is very little correlation between the two.
So first off, Monsters in my Pocket was a franchise made in USA, with popularity in continental Europe, UK and USA. It had very little influence in Japan, so I don't think that Satoshi Tajiri would have taken inspiration from it.
In March 2000, Morrison Entertainment Group, a small toy developer based at Manhattan Beach, California, sued Nintendo over claims that Pokémon infringed on its own Monster in My Pocket characters. A judge ruled there was no infringement, so Morrison appealed the ruling in November 2001
That shows you weren't the first person to consider there might have been a relation - but it was ruled as no infringement, which means there was very little, if any correlation between the two franchises. Pokémon was apparently inspired by Beetles in Satoshi's life, while Monsters in my Pocket was based off myths and legends, including things like the Abdominable Snowman.