Can a receiver see only the one-time Bitcoin address the transaction came from?
Yes, but it will depend on how you spend and receive your coins. Your change address may be visible.
Or also something like a wallet ID. Say I send 2 transactions to the same wallet. Can this receiver somehow find out that both came from the same wallet? Or can he not know this at all since only the transaction ID's are shown and obviously those are not the same?
There can be two scenarios. Bitcoin is just spending the outputs generated from previous transactions. So keeping that in mind,
You received x amount of BTC to address A in two separate transactions. Those coins are immediately associated with each other and its understood that a single entity controls that private key.
You received x BTC to address A and y BTC to address B. No direct link can be drawn immediately from them. However, when you spend x+y BTC, both of the outputs from address A and address B will be spent in the same transaction. Hence, links will be drawn between them.
If you spend them seperately in two different transactions, no links will be drawn.
