As I am sure you know, there is no need to speak Welsh to travel around Wales, but even learning a few words can make a trip more pleasurable for different reasons.
One of these, if you like languages, is that you become more aware that there is another language and culture around you.
As an English speaker, it is very easy to miss this entirely, but there are signs, and by this I mean writing on signs! Everything is written in Welsh and English, so even if you don't hear Welsh being spoken, you can read it everywhere.
In the above phrases (which you might or might not commit to memory), you will see the word tocyn 'ticket'. This appears everywhere in railway stations in Wales (not suprising perhaps), so even if you just learn this single word, you will see it everywhere. The same happens with cars. The minute you see or talk about a yellow Audi (for example), suddenly they appear everywhere, despite their comparative rarity.
Phrases are a good way to look for simple grammar patterns (if you are so inclined), and there are two obvious and useful patterns in these phrases.
Tocyn i ... 'A ticket to'. The i has several meanings in Welsh, one of which is 'to' used in the same sense as the English in 'going to'.
Oes yna ostyngiad i blant? 'Is there a discount for children?'. Welsh and English use a different grammatical structure to express ownership or possession. The word Oes is an important part of this structure. See Welsh grammar for beginners.
And for you more serious Welsh learners, there is a nice example of the t > d mutation following the number two.
See also general travel words, train and bus and holiday phrases.