Paragangians, because of having lived in space without a dream field so long, developed a system of Dream bonding through which family members and close friends can share dreams without a dream field and without being in physical contact through forming a dream bond. A dream bond is almost like a private dream field which exists between two people. It cannot cross space but can cross huge distances through matter, ie any place on a planet if they are on the same planet.
There are several factors in the formation of dream bonds.
A dream bond requires that there be a close relationship between the two people. Just being present at the birth or sharing dreams will not create a dream bond if the people are not close. Rhonda does not establish a strong Dream bond with Alexandreil, though they dream together, because she has very little affection for her husband.
A person who is present at the birth of a child can much more easily form a dream bond with the child, especially if the child is born in space, where there is no dream field. This is part of the reason Sen'tran had such a strong dream bond with Jonathan. Paragangian Mothers almost always have dream bonds with their babies, especially if the baby is space-born, unless the baby is a strictly genetic child which the mother does not intend to raise such as Alexandreil.
In general, being Space-born increases a child's potential for developing dream bonds. Because of this some Paragangian people who live on planets choose to give birth to their children in space. people living at ESM might go to ESM to give birth for example. this is why jason Scott-Harris was born in a HomeWorld Air Car.
People can Develop a bream bond by dreaming together, ie Jonathan and Jason would surely have a very strong dream bond. Jason and Serai would have a dream bond after the first time they dreamed together, with the kitten. [I'm not sure they didn't have one before that, actually]
Jason and Harris have a Dream bond, but I'm not sure how their dream bond formed. one theory is that Sen'tran took Harris to Jason's birth. I'm not sure why he would have done this though.
Lenn might have had something like a dream bond with Jason, to be able to contact him in dreaming fro the opposite side of the planet. I don't know how this could have formed. It probably has to do with Jason having dreamed so much with Jonathan and Lenn having dreamed with Jonathan before he was born. Although Lenn's Dream Bonds were all removed by the Ancients or Quetz'l so I'm not sure that theory holds.