<?php
$abs = "Bob Rob Sue";
$abby = "sometext Bob1:2 is Sue3:4 where Rob2:1 etc";
// escape each word for safe use in a regular expression, then join with pipes
$words = str_replace(" ", "|", preg_quote($abs));
// build a regular expression that finds a boundary, a word, \d+:\d+, and a boundary
$regex = '/\b(' . $words . ')(\d+:\d+)\b/';
preg_match_all($regex, $abby, $matches, PREG_SET_ORDER);
print_r($matches);