LaTeX indentation rules for Sublime Text. See usage in comments below.

Indentation Rules.tmPreferences

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
    <dict>
        <key>name</key>
        <string>Indentation Rules</string>
        <key>scope</key>
        <string>text.tex, sources.bib</string>
        <key>settings</key>
        <dict>
            <key>decreaseIndentPattern</key>
            <string>(?x)
                # \end{...} + some comments
                ^\s*\\end\{[^\{\}]+\}.*$
                # \] + some comments       
                | ^\s*\\\].*$
                # a closing brace } + some comments                   
                | ^\s*\}.*
                # \fi
                | ^\s*\\fi\s*$
            </string>
            <key>increaseIndentPattern</key>
            <string>(?x)
                # \begin{...} + optionnal {...} and/or [...] + optionnals, but only if \end{} not on same line
                ^\s*\\begin\{[^\{\}]+\}(\{.*\}|\[.*\])*[^\}]*\s*$
                # beginning of math mode display \[ + spaces
                | ^.*\\\[\s*$
                # backslash + a command containing no backslashes + opening bracket or arrobase i.e. \textbf{ or @misc{ + any character
                | ^.*(\\|\@)([^\\]+|def.*)\{[^\}]*$
                # }{ for ifthenelse struct or a single opening brace { + some characters
                | ^\s*(\})*\{.*$
                # \if...
                | ^\s*\\if(num|dim|odd|vmode|hmode|mmode|inner|cat|x|void|eof|true|case|beamer)\S*\s*$
                # else
                | ^\s*\\else.*$
            </string>
            <key>unIndentedLinePattern</key>
            <string>(?x)
                # \else
                ^\s*\\else.*$
            </string>
        </dict>
        <key>uuid</key>
        <string>02EB44C6-9203-4F4C-BFCB-7E3360B12842</string>
    </dict>
</plist>