Not sure how this can be auto generated by packageDev, if at all, but dropping the following into the package gives access to commenting/block commenting, in sublime.

Comments (Zeek).tmPreferences

<?xml version="1.0" encoding="UTF-8"?>
<plist version="1.0">
<dict>
    <key>name</key>
    <string>Comments</string>
    <key>scope</key>
    <string>source.zeek</string>
    <key>settings</key>
    <dict>
        <key>shellVariables</key>
        <array>
            <dict>
                <key>name</key>
                <string>TM_COMMENT_START</string>
                <key>value</key>
                <string># </string>
            </dict>
            <dict>
                <key>name</key>
                <string>TM_COMMENT_DISABLE_INDENT_2</string>
                <key>value</key>
                <string>yes</string>
            </dict>
        </array>
    </dict>
</dict>
</plist>

Anything between two forward slashes seems to get picked up as a pattern, e.g.:

local subnets = vector(172.16.0.0/20, 172.16.16.0/20);

The regular expression used to color the IPv6 subnet type does not include the ones place of the subnet mask sometimes. Examples are [100::]/64, [64:ff9b::]/96, and [2001:db8::]/32.

This blog post provides a good regexp. I modified it to replace all occurences of "d" with [0-9], removed the two occurences of "s" (not sure their purpose), and added the brackets surrounding the IPv6 address to conform to Bro's standard representation.

Probaby a bit of modifying necessary since I haven't tested it myself, but regex101 liked it. Thanks for this syntax plugin!

Here it is: ^[((([0-9A-Fa-f]{1,4}:){7}([0-9A-Fa-f]{1,4}|:))|(([0-9A-Fa-f]{1,4}:){6}(:[0-9A-Fa-f]{1,4}|((25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])(.(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])){3})|:))|(([0-9A-Fa-f]{1,4}:){5}(((:[0-9A-Fa-f]{1,4}){1,2})|:((25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])(.(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])){3})|:))|(([0-9A-Fa-f]{1,4}:){4}(((:[0-9A-Fa-f]{1,4}){1,3})|((:[0-9A-Fa-f]{1,4})?:((25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])(.(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])){3}))|:))|(([0-9A-Fa-f]{1,4}:){3}(((:[0-9A-Fa-f]{1,4}){1,4})|((:[0-9A-Fa-f]{1,4}){0,2}:((25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])(.(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])){3}))|:))|(([0-9A-Fa-f]{1,4}:){2}(((:[0-9A-Fa-f]{1,4}){1,5})|((:[0-9A-Fa-f]{1,4}){0,3}:((25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])(.(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])){3}))|:))|(([0-9A-Fa-f]{1,4}:){1}(((:[0-9A-Fa-f]{1,4}){1,6})|((:[0-9A-Fa-f]{1,4}){0,4}:((25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])(.(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])){3}))|:))|(:(((:[0-9A-Fa-f]{1,4}){1,7})|((:[0-9A-Fa-f]{1,4}){0,5}:((25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])(.(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])){3}))|:)))(%.+)?(]/([0-9]|[0-9][0-9]|1[0-1][0-9]|12[0-8]))$