How to Determine ATMPTF Level
ATM Client Method 
In ATM, go to the Administration Menu and click the ATMPTF button.  This will return a list of the PTF's installed on the system for the ATM environment you are logged into.  Note: you may have to scroll down to see all of the entries.  The latest ATMPTF installed will be at the bottom of the list

Database Query Method - 
On an iSeries Green screen command line - 
Type STRSQL and press Enter 
Then type the following replacing 'y' character accordingly and press enter.  
SELECT * FROM ISTPCy.ATMPTFLOG 

Where 'y' is the second character of the XA environment name.  If XA name is MM library is ISTPC with no 'y' character.  If XA environment is XB the library name is ISTPCB

PTF's will be listed in the results similar to the following - 
Screen shots of each page will show the install history.