Listing Bolts on the Isometric Bill of Material is straight forward like any other part.  However, if you want to have the Bolt Size and Bolt Length show up in the Isometric Bill of Material under the Size Column then you need to set the Alternative Text ID “-538″ as follows:

In CADWorx Plant Professional 2014, use I-Configure and setup as follows: 

In CADWorx Plant Professional 2015, use the new Isogen Interface and setup as follows: