Dylan will not be able to influence their behaviors, but he will be able to tap into the hivemind and communicate with them–one hivemind to another. He'll recognize that in their infantile state, their only thought is to spread to other hosts. This isn't their home, everything is unfamiliar to them, and when in a new location their first instinct is to overtake the local populace. They can't survive without hosts, as hosts are the only way they have to propagate.

Given that, while similar in nature but still very different, the Pod People will recognize Dylan's symbiote as a presence already within the bodies Dylan portions off his goopy bits into. This will prevent them from getting infected.