Add a rule: Points must be covered by lines - The user would be able to select multiple feature classes for the point and line features. This would be a quick and dirty way to see if your entire Utility Sys has been snapped up properly...
Add Attribute Logic to Topology. Example: myPolygon must contain one point where point.location_type = 'Hospital' (give hawatson credit for this)
Add Logic (And, Or, etc.) to Topology rules Example: Vales Must Be Covered by Mains OR Laterals Example 2: Hydrants AND Valves Must Be Covered by Mains OR Laterals.