Lloyds coaches?

As with all Traws Cymru journeys, buy on the bus as you did a few days previously coming up from St Davids. All the Traws Cymru services are what you call city buses.
They are not coach services, as in Greyhound or National Express. So no advance booking.
They can't sell out.
And you are joining at the start point. If it gets really busy the late joiners would have to stand, this being a bus service.

Just a £6 single fare on this one, assuming you are only going to Porth.

If it was astoundingly busy out of Aber, then Lloyds are only based in Machynlleth (a few miles up the road) and they would turn a relief vehicle out, but frankly the reverse is likely to be true- that it will be a quiet bus.

I know the routes are limited due to the bank holiday and I just want to be sure there is a T2 departing at 8:45 am. Im getting conflicting info on that between sites. Also, why does it come up with times for the day before I requested in the search? Its frustrating to get the actual date I want. Like on the left it says departing sunday when I put in monday.

Thank you for your help!

As on the other question the reason for the date difference is probably down to the time difference between the two countries.
When I take a live stream from the PNW my computer automatically changes the due time from PT to GMT/BST.
Presumably something similar is happening here.
On Lloyds timetable they call the Bank Holiday a public holiday (the terms are interchangeable) so it is their Sunday and Public Holiday timetable which seems to match the one on Traws Cymru, where they call it a Bank Holiday!

I would consider going by train from Aberystwyth to Porthmadog. One change is needed at either Dovey Junction or Machynlleth. No need to pre-book - just buy ticket at Aberystwyth station. Alternatively, purchase a ‘Explore Cambrian Coast Day Ranger’ for £14 (£9.20 with Railcard) as it is almost the same price as the fare. This would allow you to hop off and then catch a later train -though the frequencies are not that great. Nice places to hop off would be Aberdovey (Aberdyfi) and/or Barmouth.

Train schedules >https://www.nationalrail.co.uk
https://www.visitwales.com/destinations/north-wales/explore-cambrian-coast-railway-line
http://www.railrover.org/pages/explore-cambrian-coast-day-ranger.html

The bus takes a totally different route than the train between the two towns- the train basically hugs the coast, the bus cuts through the mountains, so two completely different types of scenery.
The two modes of transport have almost no common ground, except start and end points.