Probably.
I work with a site just like yours, and can obviously say only so much. But consider these things:
The reason you're getting good hits on restaurant pages is that most restaurant websites suck. Many might have only a facebook page, etc. Presently you're being "told" by Google that it's only going to send you individual restaurant traffic, but you feel the value is in the aggregator.
Which brings us to the uncomfortable truth.
Google is at war on aggregators and is doing everything it can to hide them. In the last 8 years it has pushed them further and further down the rankings, while having it's own aggregator services appear at the top of the rankings. Google don't want you to exist because being the middleman is where they make their money. A while ago there were some cases trundling through the courts, but no idea what happened with them.
Also, most of your competitors like tripadvisor/bookatable/opentable/timeout/resdiary/etc. sell bookings directly to the restaurants. They'll charge per cover (per head). If not, they'll be upselling something else (tripadvisor has recently been pushing a lot of "experiences" where it'll be making a big commission). Some of them actually make most of their money by also selling restaurant management software, etc. You haven't given your site, or said how you make money, but can you make that kind of money, and can you do direct sales to restaurants? They are hard to sell anything to as most of them are constantly on the breadline. If you're hoping to slap a bookatable widget on each of your listings and make money, prepare to be disappointed, it might cover your hosting and a few beers.
Finally, I hope you don't find this too rude, but are you really following good, modern SEO practice? As if I search "Newtown restaurants Ireland" then tripadvisor, your main competitor, is sitting pretty at the top. But your site is nowhere to be seen (I see no independent aggregators). Perhaps you've given a bad example as Google is insistent on trying to show me restaurants from Newtown, Wales. I also tried a few restaurant names in Newton and still couldn't figure out what your site is.
EDIT: Just saw you actually posted your site, so if I search "Rathmines Restaurants" you're 16 in google results. It's not bad, but you can see what the others are doing instead ("the top 10 restaurants in Rathmines"). You also see that if you go to any of the top results, a bunch of listings have "reserve" buttons, and use something like the opentable widget.
Plus points for having full text menus, your site is clean and fast, it's a good achievement. I just do wonder how you're going to make money on it. I would definitely try putting opentable widgets in asap so you can get a much better idea of what sort of revenue you could generate and just how much you'd have to grow it to make it worth the investment. In my experience though those widgets are pretty lacklustre unless you can figure out a way to make money directly from the restaurants.