"In the presence of the protectors,
I arouse the intention to gain full enlightenment.
I invite all beings as my guests
And shall free them from cyclic existence"
The "protectors" are the buddhas of the ten directions, who, through their omniscience, are aware of those who take the bodhisattva vow, and in that sense present. Full enlightenment is the enlightenment of a buddha, which is greater than that of a pratyekabuddha or arhat, because their accumulation of merit and wisdom is greater. And because they are greater, they have greater resources for helping others. A buddha aims to free all beings from ignorance, so in that sense they are guests of the buddha.