How can I use Bottle Summary to output the bottle number as well as the trip order to a .btl file?

Yes, it is possible to include bottle ‘serial numbers’ through the use of a .sn file, which is a user-created file containing information about the bottles you have fired. Creating the file before processing your data in Seabird Data Processing’s Bottle Summary module is necessary for the process to work. If a .sn file (same name as input data file, with .sn extension) is found in the input file directory, bottle serial numbers are inserted between the bottle position and date/time columns in the .btl file output.

The format for the .sn file is:
Bottle position, serial number (with a comma separating the two fields)