It's not about the theme but the plugins.
Here 9 top plugins for good search engine WP experience.
1. WordPress SEO by Yoast
http://wordpress.org/extend/plugins/wordpress-seo/
Download this plugin now and use it on every WordPress site you own.
This plugin, in my opinion, is as important as the WordPress installation itself.
It's also extremely easy to use.
2. Simple URLs
http://wordpress.org/extend/plugins/simple-urls/
This plugin is great. You can track outbound links and control them completely right
within the WordPress backend. If you add Disallow: /go/ into your robots.txt file it
will also stop any authority from passing through the link itself.
3. RB Internal Links
http://wordpress.org/extend/plugins/rb-internal-links/
Although this plugin hasn't been updated in more than two years, it still should be
included in every WordPress installation. This plugin helps with internal linking.
4. NextGen Gallery and Lightbox Plus:
http://wordpress.org/extend/plugins/lightbox-plus/
http://wordpress.org/extend/plugins/nextgen-gallery/
These two plugins have been combined into one entry because they work hand-in-hand.
Lightbox Plus uses Colorbox ? a lightweight jQuery image gallery script that is the friendliest
for performance and doesn't hinder on-page SEO. Although Lightbox is included as an
option within NextGen itself, Lightbox Plus offers a lot more options for the appearance
and behavior of Lightbox's execution.
5. Widget Logic
http://wordpress.org/extend/plugins/widget-logic/
This plugin works specifically with your widgets. When installed, an extra option is added
into each widget where you can define exactly where that widget should/shouldn't appear.
This is great when you want to control what content appears in which sections of the site.
6. Members
http://wordpress.org/extend/plugins/members/
You may find that the default user roles provided by WordPress aren't enough for you to
control the access that you want. This plugin adds flexibility to edit existing user roles as
well as adding additional user roles. The plugin also comes with easy to use widgets and
shortcodes so you can limit content based on the user's role.
7. Use Google Libraries
http://wordpress.org/extend/plugins/use-google-libraries/
This very simple plugin that substitutes JavaScript libraries called locally on your own
server with Google's own CDN. This saves on bandwidth, keeps using compressed versions
of the scripts, and increases the chance that a user already has these files cached and
therefore increases the general performance of your site.
8. W3 Total Cache
http://wordpress.org/extend/plugins/w3-total-cache/
While we're on the subject of performance, W3 Total Cache is the most powerful and
comprehensive caching plugin available. This plugin handles everything from combine and
minification for both CSS and JS to HTML linebreak and comment removal, disk caching,
browser caching and more.
It's useful to test any settings out to ensure that there are no issues once enabled and
deployed but most of the time W3 plays ball with your WordPress installation.
9. Gravity Forms
http://3doo.rs/gravity
This is the best plugin available. Although paid (from $39), this plugin is a must have
on any WordPress installation and pays for itself.