TheOptimizationIdiot - 2:16 am on Mar 4, 2013 (gmt 0)

Part of it depends on how you actually make the text bold. Meaning, if you use <span class="b"> it's not exactly the same as <b> or <strong> but according to the HTML5.1 docs what you're talking about seems to be inline with the intended use of the <b> element.

The b element represents a span of text to which attention is being drawn for utilitarian purposes without conveying any extra importance and with no implication of an alternate voice or mood, such as key words in a document abstract, product names in a review, actionable words in interactive text-driven software, or an article lede. [w3.org...]