Personalization rules are under attached to the rule "Conditional Renderings". Here is the path to follow looking for your missing rule.
A tag is the glue between rules and elements. You will have a custom tag under the item,
/sitecore/system/Settings/Rules/Definitions/Tags/. Lets say that are called
Membership Status. i.e
Under the item path
/sitecore/system/Settings/Rules/Definitions/Elements you should have a Element where you custom rules exist. You will create a new element called
Membership Status. In that Element there is a
Tags item and a child called
Default. Path would be
/sitecore/system/Settings/Rules/Definitions/Elements/Membership Status/Tags/Default. In the Tag multilist, in the custom tag, you select the Tag you created in step 1 above.
Finally you will have a custom Tag under the item
/sitecore/system/Settings/Rules/Conditional Renderings/Tags. I usually name the tag custom. In the multilist, in the custom tag, you select the Tag you created in step 1 above.
Your rules in your Element Membership Status and tied to the rule Condition Renderings via the Tag Membership Status.