How ca you determine if two molecules have ion-dipole force just by loking at it?

You can tell if it's an Ion dipole if it is a force between ion and polar molecule. Just remember all these: an ion is an atom that gained or lost one or more electrons. It has negative or positive charge. A cation is positively charged. An anion is negatively charged. By knowing these, you can understand how they will bond together. 

Ch4 and ph3 are both covalent since they are composed both of non-metals.    ch4 is non- polar because of  london forces and has a geometry of tetrahedral  ph3 , on the other hand, is umbrella shaped polar and has dipole-dipole intermolecular force (imf) . since ph3 is polar, it has a stronger imf